Part 2: I’m serious. They really do call me Dr. Prism.

At least the opticians do.  Nina always gives me that look that says “surprise, surprise” when I tell her that my patient needs some prism.

Since I started prescribing prism in greater numbers, (I’ve prescribed more prism in the last 7 months than during any of my nine years of practice) I’ve seen all sorts of interesting things happen during the exam.

There was the 12 year old girl who our technician couldn’t refract to anything better than 20/200.  After a few binocular tests and the proper prism put in front of her, she coasted easily to 20/20 with each eye.  I’d never seen anything like it.  But then again, I’d never looked at that as the potential problem.  And I have to admit, it’s a little embarrassing considering I’ve practiced for almost 10 years.

And I see this almost every day.  People of all ages who fall asleep driving, can’t read for more than 20 minutes, high school seniors who can’t make it all the way through their SAT testing and I wonder how many I missed over the years.  Patients we would just call amblyopic because there was no other explanation.  All because their eye muscles don’t want to efficiently aim their eyes at whatever they’re trying to concentrate on.

Now, for my OD friends…I do not consider myself a binocular guru.  I’m not planning on writing a book or opening up a specialty practice.  I’m just looking at an aspect of their vision and checking their response to holding a prism in front of the eyes.  I’ve been shocked at how many times my patients say that things look clearer as well.

And the tricky part of all this is how well most of us can compensate when our eyes start fighting each other.  But compensating usually means slowing down, stopping, or avoiding any kind of comprehensive reading.  Those of us who are halfway intelligent can be fairly successful in life despite this.

So maybe I’m just behind the times and Dr. Chung and Dr. Espiritu (my friends and classmates), they probably discovered all this years ago.  I know Dr. Nate did!  I like to think that the busy-ness of my prior practice in Texas did not afford me the time to delve in to these things.  But that’s not much of an excuse.

So if you experience fatigue around the eyes that occurs regularly, quit blaming your sinuses if you haven’t had a good binocular work up during your eye exam.  If your eye doc didn’t make you see double at some point during your last exam AND didn’t solve all your vision problems, then mention this article to them next time.

About admin

Eye/vision doctor in San Antonio. Serious sports fan. Goofy dad. Husband who tries hard. Never met a bag of beef jerky that I didn't like. Except salmon. San Antonio, TX ·
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  • EyeBob

    Not for nuthin’, but the two graphics representing optical prism seem to show light being deviated oppositely. One towards the base, one towards the apex.

    Just sayin’

    • Ah, you’re right! Good prism pictures are hard to find.

  • Alex

    Hi Dr. Deviney,

    I sent you an email with this question but I thought I would post it on here as well.

    I read your article on prism correction for people with eye fatigue. I’ve had eye fatigue/aching for the past 2 years as a web designer and I went through the regular gammut of things to correct it. I have a slight astigmatism of –0.75 in my left eye and thats about all thats wrong with my clarity of vision. However I still feeling the aching in my eyes even if I wear the spectacles to correct that. (Those glasses only correct the astigmatism and a +.25 sphere in my left eye as well. When I went to the optometrist last though she did a positive fusional convergence test on me for near vision and said that I only went 5 clicks before see a slight blur in my near vision. She recommended trying prism glasses with base in prisms of 2b1 in both the right and left eye. I’ve tried wearing them at the computer and haven’t seen the greatest benefit yet but I’m wondering if wearing them all the time will help at all. She said only to wear them for near vision tasks but I’m wondering why that is? The reason I’m asking you this is because you seem to be knowledgeable on prism use and I’m trying to figure out why is causing all the aching in my eyes from using the computer. I believe the aching has to do with my extraocular muscles because if I roll my eyes very frequently during the day clockwise and counter clockwise it seems to help some with the symptoms.

    Thanks for your time and I appreciate your response.


  • Alex

    One thing I forgot to mention is my eyes frequently go blurry and sometimes double vision. When this happens and I look at a stereogram the divergence ones pop out at me so I know my eyes are drifting outwards at least a tiny bit. Would the base in prisms help with this as well?


  • Hi Alex. Thanks for reading and for your questions. If you are still feeling an aching feeling in the eyes, then I would suggest getting a pair of computer progressive lenses. I use Hoya Tact or Shamir Office lenses which are designed to give you some focusing power for the distance of your computer screen (at the top of your lens) and a little more focusing power for items held even closer (at the bottom of the lens). In addition to the prescribed prism, it should definitely help relieve your eye strain.

    Of course, no matter what, if you look at a computer screen all day then you are going to feel some eye fatigue. So you still want to take some kind of a break about every hour where you go look out the window or somewhere farther than the distance of the computer screen.

    As far as wearing the glasses all the time…I can wear my Tact lenses all day if I wanted to, but they are not designed for that. Use caution and make sure you can see clearly and comfortably at a far distance before venturing far from the computer.

    I agree with you that the aching is from the eye muscles. Rolling the eyes around helps to stretch them out after converging for so long.

    Try the computer progressives. They did wonders for me. Good luck and keep us posted!

  • Alex

    Thanks much for your response it was very helpful. I have a few more questions for you if you don’t mind. I currently have “computer glasses” that have +1.00 diopter in both eyes for magnification. It also has correction for my astigatism in the left eye. I haven’t gotten really any relief from wearing these however. What is the difference between the lenses you suggested and what the doctor I saw gave me for computer glasses? Another question I had is that whenever I wear the glasses to correct my astigatism, my eyes feel odd like they’re pulling and it’s very uncomfortable. Is this because my eye can’t tolerate the astigatism correction? I read that on this website:

    I want to use the glasses to correct my slight problem but if it’s making it worse I obviously don’t want to.

    The third question is how do I obtain these lenses from Hoya or Shamir? Do I have to go to a doctor to get them or are they available online? As for the aching in my eye muscles, since the rolling exercise seems to help is there anything else you could also recommend to stretch the muscles out and keep them from getting tight? The odd thing is that other people in my office don’t seem to have the problem of the aching eyes but I do and they spend the same amount of time on the computer as I do. I’m wondering if it’s a tension problem. Sorry for this huge post.

  • Alex

    Dr. Diveney,

    How can I tell if my convergence muscles are too weak for computer use? Perhaps they aren’t strong enough to hold this contracted position at near point for so long and that’s why I have to roll my eyes constantly to try and rid myself of the eye aching? Any ideas?

    Thanks for your help

    • I don’t know that I can specifically tell you if your eye muscles are too weak for computer use. Many experts argue that our eyes were not designed to be turned inward for hours at a time, whether it’s for reading or computer use. Your eye muscles wouldn’t be like everyone else’s in your office because the natural resting posture of their eyes are not going to be the same as yours. When your eyes get tired, they want to diverge outward. But you need them to continue to converge inward in order to concentrate on your computer screen. The main difference between the computer prescription you have and the one I use is that mine is a multifocal lens with computer distance at the top and nearer reading distance at the bottom. There’s no guarantee that this would help your problem.

      I’m afraid I don’t have enough info to tell you if you are unable to tolerate astigmatism correction, but that is a possibility.

      I don’t believe that you can get Hoya or Shamir lenses online. At least, I’m not aware of how you would do that.

      Another option involves eye exercises to help condition the muscles to better converge and diverge. There is a computer program available through eye doctors called the HTS Home Vision Therapy program. Along with your computer prescription (or Hoya/Shamir lenses) this program may ultimately be your best option.

      I hope this helps.

      Jason Deviney

  • Alex

    Thanks for your time and answering my questions I really appreciate it. I’m going to continue wearing these prism lenses and doing the eye rolls and see what happens. I agree that my eyes want to diverge when they get tired because I can feeling it happening frequently throughout the day. They’ll get tired and my vision will go double. I’ll come back and post in a week or two with my progress. I do want to try out the HTS vision therapy program. The only way to get this is through an optometrist?

  • I believe that specific series of programs is only available through doctors, but you could call them to find out. According to the website: call 888-810-3937 for a free sample program.

  • Alex

    Well I’ve found that the only thing that does help me are those eye rolls. I literally have to do them all day long while at the computer for them to work. I’m not sure why my eyes are always tight.. I’m supposing its from staring at a near point all day long. Besides the eye rolls, do you recommend any other stretching exercises for the eyes I can do? I don’t believe its a weakness problem anymore because I did strenghtening exercises for my eyes for months with no effect. It was only recently that I started doing these eye rolls a lot and it seems to be helping. I’m just wondering why I have to do it so much. What I do throughout the day is take microbreaks and each time I take one of those I roll my eyes for the break period in both clockwise and counterclockwise direction as well as moving them up, down, left and run. Any ideas on other ways I can stretch as well?

    • Alex, I don’t really have any normal regimen of prescribed exercises like you’re referring to. And as far as your muscles always feeling tight, I’m not sure that I can give you a good answer to that one.

  • Alex

    One thing I forgot to mention is that I’m one of those people that no matter how much I stretch I always feel tight. I’m wondering if that has something to do with my eye muscles as well. Thanks for your time

  • Alex

    Hi Dr. Deviney,

    I was doing some research and I found some information that correlates with the problem I’m having.

    Heres an excerpt from the article:

    This is a condition where the eyes prefer to be positioned outward, but the eye muscles successfully overcome this deficiency. But the effort to achieve this coordination sometimes results in eyestrain and even occasional and intermittent double vision. Exophoria is often easily treated with exercises which stimulate the eye muscles to work properly and the focusing system to “lock” onto the object(s) of regard in the visual field. When the eye muscles fatigue, exophoria can become, intermittently, an exotropia. Doctors often use a stereo vision apparatus, such as polarized vectograms (3-D transparencies) with polarized glasses or red-green 3-D cards with red-green glasses, which allow the user to have constant feedback as to the position of the eyes and whether or not they are working together.

    When I last went the opthamologist he said that when he covered one of my eyes the other drifted out slightly. I’m wondering if the reason I get some much eye ache is because my eyes prefer to stay aligned outward but I’m forcing them to stay in with muscle exertion. Do you know of any good ways to correct this problem? The eye doctor I saw couldn’t suggest anything. Right now I’m working with pencil pushups and stereogram magic eye pictures.

    Thanks for your time


    • The best program I know of is the HTS HOme Vision Therapy program that I mentioned earlier. The nice thing about the program is that it tracks your progress and makes it easy to monitor as your eyes improve.

  • Alex

    I’m definitely going to ask my optometrist next time I go in about this program. In the meantime though i’ve been doing a lot of eye rolls which seems to be the only thing that helps. I believe my problem has a lot more to do with the convergence muscles than it does with accommodation. I’ve been doing the eye rolls a lot though… perhaps more than i should be. I’m not really aware of what the proper amount of time to be doing them everyday is though. I know you can’t diagnose this problem online but I wanted to ask your opinion anyway. As I said in one of my previous posts, I believe I have a problem with tightness in my eyes. You also said that converging for so long will cause your eyes to tighten. But when doing eye stretches like eye rolls every day, do you think over time the muscles will finally stretch out so I don’t have to do these exercises like 30 minutes a day? It feels like my eye muscles are overly tight or something.

    • I agree that convergence is the bigger issue for you vs. accommodation. When vision therapy programs are prescribed for convergence insufficiency, they are often prescribed for 3 to 4 months. I would imagine that if you could do these exercises 20 minutes per day (5 days per week), then there’s a chance you might see SOME difference. But it’s kind of like going to the gym… if you only go inside, stretch, and then leave…then you might not be conditioning the muscles in the most ideal way.

  • Alex

    You make a good point… Do you think a better course of action would be to stretch and strengthen them then? Do eye rolls and then some sort of convergence exercise to strengthen the muscles?

  • Alex

    Ok well I wore the glasses I have for astigmatism full time for 3 days and I can say pretty fairly that they made my problem worse. I have more pulling and tightness in my left eye than before when I didn’t wear them. Not sure why this is because I see clearer when I have the glasses on but it makes my eye feel worse. It’s hard to describe this sensation so “pulling” is one of the ways I put it. It’s just extremely uncomfortable.. I wanted to try and wear these glasses for a full week to see if I had to “break” them in but I just don’t see how that is going to happen when it makes my condition worse off.

    The reason I’m reluctant to go back to an opthalmologist for this problem is because the last time I did (around 3 weeks ago) he said that was nothing wrong with my eyes and I shouldn’t be having any problems. I tried to explain to him the problems I was having and he shrugged his shoulders. I want to thank you for helping me out on your blog I really appreciate it. You’ve been more helpful than the doctors I’ve gone to see so far and we haven’t even had a visit. Do you recommend I go to another opthalmologist to have my eyes looked at again to see if perhaps my prescription is wrong or if I have no tolerance to astigmatism correction?

    I feel like this could be a double edged sword. If I don’t wear the glasses, I have to look at the screen with a slight blurriness in my left eye which I think is causing eye strain and serious fatigue. If I do wear the the glasses I get that massive pulling/tightness sensation in my entire eye region for the entire time I wear them. It doesn’t get better over time like I thought it would and the sensation doesn’t change if I’m looking at a distance or near. Sorry for this huge post but I just had another horrible eye pain day.



    • Hi Alex. I’m sorry you had a bad eye day! Some people have trouble tolerating any astigmatism correction. So that could be a problem for you. It would take some trial-framing to try to figure that out.

      As far as going to see another ophthalmologist, I know there is often confusion in the general public concerning the differences between optometrists (like me) and ophthalmologists. We are trained in different ways regarding the eyes. Optometrists are extensively trained and educated to diagnose and treat many eye conditions/diseases and we go through additional extensive training to help people with their vision problems. Ophthalmologists (OMDs) are highly skilled in surgery and eye diseases (in addition to their medical school training), but I think it’s fair to say that vision correction of the problem you are having is not a specialty of theirs.

      So I wouldn’t go see another OMD at all for this problem. Go to to see if someone is near you who specializes in your type of binocular vision problem. I’m glad I’ve been some help for you. Good luck.

  • Alex

    Yeah it’s definitely not an issue of seeing an opthalmologist over an optometrist or anything it’s just my insurance is stupid and won’t pay for an optometrist visit but once a year however they will pay for ophthalmologist visits unlimited. It’s dumb I know. Thanks again for your help.

    • Ahh, but that’s what most patients think. Vision plans that most optometrists accept DO only cover 1 visit per year for “routine” eye exams. That means straightforward, no complaint vision exams. You are far from routine at this point. We see patients every day and use their health plans to cover their visits using medical diagnoses such as eye pain, headaches, dry eyes, etc. as needed. I’ll bet you a dollar if you check your health plan’s website (or provider directory) you would find a ton of optometrists listed as providers. Then call one up, ask them if they can bill your health insurance to evaluate the pain in your eyes (don’t be sneaky, just tell them your problem, your history, your situation with your vision plan etc…) Your eyes are part of your body and are covered by your medical plan if they hurt, I guarantee you that.

      You are in the Milwaukee area, right? Try this page and see what happens:

      Insurance companies try to confuse you so that you won’t abuse your coverage. They don’t want to give their money away. You’ve gone to this much effort with me. Find someone who can truly help you. It won’t get better on it’s own.

  • Alex

    Thank you I’m definitely going to look into this more then and try to get in to see an optometrist. There was one around here that I was particularly interested in because he has a PRIO vision tester and I wanted to see how my eyes reacted to it. I guess I’m worried because if they send in the bill wrong the insurance company is going to deny it and try to bag me with it. I’m going to look at that link you sent and call some optometrists on Monday and see if they would bill as eye pain instead of routine and see what happens.

    Have you ever heard of the PRIO tester before? I guess it’s supposed to simulate the computer screen so a more accurate prescription can be found. I know for sure now that the glasses I currently have make my problem worse because I didn’t wear them today or yesterday and that pulling sensation went away.

    I will tell you that I called up the insurance company a while ago and asked them about that coverage and they said that only one visit to the optometrist was covered. I guess they consider an ophthalmologist and specialist but optometrists aren’t which is ridiculous.

    You also said something about checking on the insurance website to see if there are optometrists listed as providers. There are a lot of them but this insurance seems to regard the eyes as a meaningless organ since the vision plan isn’t very good. I will make the phone calls on Monday and see what I find out. Thank you for the advice and I’ll let you know what happens.

    • I have heard of the PRIO tester, but have no experience with it. I would still recommend someone with expertise in binocular vision vs someone with a PRIO tester.

  • Alex

    I called the insurance company and you are absolutely right that they do let you see optometrists it’s just how the physician bills it. So i will make sure that I say its for a medical reason rather than the routine visit.

  • Alex

    When I call the optometrist on Monday i’ll be sure to ask about their experience with binocular vision issues

  • Alex

    I was reading this post again and I forgot to ask you how the prism glasses helped with your eyestrain. I too have 2 diopters of base in prism in my one of my glasses but when I wore them for an entire days work after I took them off I felt kind of dizzy. You said that after putting the lens in front of your eye (the base in 2 diopter if I’m not mistaken) you felt instant relief. Could you please elaborate a little further on how they made a difference for you?

    • It just felt like my eyes were able to relax when I held the lens in front. Since my eyes want to rest in an outward position, the prism meant that I didn’t have to converge my eyes quite so much to overcome it. It took me a couple of days to get used to it, but I didn’t experience anything that I would describe as dizziness. However, initially when removing the glasses the whole world would shift back and that took a little getting used to.

  • Alex

    Yeah I’m getting the same thing too when I wear the glasses. My eyes naturally want to sit outwards as well (confirmed by the doctor). When I take them off it takes a tiny bit to get used to seeing without prisms in front of my eyes. Since I have 2 diopter base in lenses, why wouldn’t I want to go 4 diopter base in then to reduce the convergence stress even further? You talked about that in your article as well.. do you have 4 base in for your glasses?

    • Well, 4 base in for each eye could be too much to tolerate and your eyes would strain trying to overcome that. It could cause double vision, but impossible to say without trial framing it. I have 2 base in in front of both eyes for a total of 4 base in. Yes, you can have prism and the sphere that you used in your example.

  • Alex

    Another thing I forgot to ask.. is it possible to have prism and sphere in the glasses at the same time? I’d like to get a pair of glasses made that have 2 base in prism and +1.00 diopter in my left and +.75 in my right eye. That would be my godsend.

  • Alex

    Well made some phone calls today. Trying to go in and see an optometrist this week for binocular vision problems. She’s a vision therapist but is also an optometrist. I did call my previous doctor and asked why I didn’t get prescribed the sphere in my prism glasses so I would have 2 base in as well as 1.00 diopter in my left eye (.25 for my slight farsightnedness and .75 for the computer) and then .75 in my right eye. They said I would have to get a new pair of glasses to get that which sucks. However there was a contradiction in what they told me when I was there for the visit and now.

    This time when I called the person I talked to said that I should wear the glasses with prism all the time but the doctor said when I went in there for the visit only to wear them on the computer. I’m not sure which is right… all I know is when I wear the prism glasses and look into the distance something is definitely off. What do you think?

    • I would really need to see the records from your exam to be able to comment accurately on your question. Sorry about that. But sounds like you’re on the right track with the new doc you’re looking in to.

  • Alex

    Sorry I’ve bombarded you with a lot of these questions.. I know you can’t accurately diagnose me without seeing me in person but I want to say again that you’ve been a great help.

    • No problem with the questions, Alex. I wish I could be of more help. Feel free to ask more. I will answer them as accurately as I can.

  • Alex

    Thanks I really appreciate it. I will probably have a lot more questions for you coming up (i have an appointment scheduled on aug 2nd with that binocular vision optometrist) so I’ll let you know how that goes. Thanks for taking the time and be willing to help out. This conversation also might help others having these problems as well.

  • Alex

    Hi Dr. Deviney,

    Ok went to a vision therapy optometrist and here is what he found out about my eyes:

    He said my eyes don’t team very well. When he ran a test with bring a pen closer to my eyes and then pulling it away from my eyes, the pen always went double when he was pulling away. He said with this my problem was that when my eyes drifted outward and went double I have a hard time bringing them back in. I’m not sure what this indicates.

    He also said that my eyes have trouble keeping things in focus with accommodation. He prescribed +.37 sphere in right and left lenses for me and didn’t prescribe the astigmatism correction. The lens material was CR 39.

    I’m going back for a vision therapy consultation because that is what he recommended to get first choice but since it’s so expensive I want to try the HTS vision therapy program first.

    I just put in the prescription today for the lenses. I personally don’t see how having lenses that are in between +.25 diopters and +.50 would be more beneficial for my eye aching problem. Any ideas on this?

    But anyway he said the two main things wrong were some eye teaming issues and accommodation. Look forward to hearing your response.



  • Alex,

    Sorry about the delay in responding. Took a few days off…

    Again, it’s hard to comment on the +0.25 and +0.50 without seeing your exam records. Sorry to cop out on that, but there’s no way my response would be accurate without seeing more.

    Keep in mind that vision therapy is not a quick fix, but is probably your best bet. It’s a matter of re-training the eyes to respond appropriately to the proper stimuli. It’s like physical therapy for the eyes and it will not work immediately. Think of people retraining their muscles to walk again after a car accident…it takes time and it’s always takes longer than you want it to.

    But research has shown that a combination of home exercises and in-office exercises is the most effective treatment. It’s that doctor’s responsibility to gain your confidence. But it sounds like this is your best option. Give it 3 months (give or take) and it may end all your vision problems for good.

  • Alex

    Hi Dr. Deviney,

    That’s no problem I appreciate you taking out the time. When you say retraining your eyes to respond to the appropriate stimuli, what do you mean by that? I understand you can’t comment on the +25 +50 correction. I’m curious as to why after all these years of computer use, my eyes wouldn’t have adjusted to this type of work. I’m wondering if the computer use actually caused my eyes to be this way and in pain.

    I’m going in for the vision therapy consultation they scheduled me for this Friday. They are supposed to tell me what the vision therapy program entails for me and stuff. I’m going to ask what their diagnosis of my problem is when I go there. Hopefully that can give me a clue as to what is wrong with me. He did say I had some eye teaming and focusing issues but didn’t specify a condition or anything so we’ll have to see.

    • Hi Alex,

      I’m curious to hear about your VT consultation.

      Your eyes may have never adjusted to computer work because they probably always wanted to relax outward and have reached a point where they can’t really take the strain anymore. The eyes are not designed to converge continuously for hours at a time. Our eye muscles naturally want to point straight ahead or relax further outward. What VT should do is condition your eyes to overcome this fatigue by “over-exercising” with high demand convergence and divergence activities in the hopes that the eye muscles will make the everyday work of computers seem easier.

  • Alex

    Thanks for the post. No problem I will post on here after I go to the VT consultation on Friday. With the over-exercising with high demand convergence and divergence, I’m curious as to why you would want to do divergence if the eyes already want to be aligned straight ahead. Wouldn’t doing divergence just promote this to happen more often? On my own I’ve been focusing solely on convergence exercises because I believed doing more divergence ones would just defeat the purpose of trying to train my eyes to see better up close. What are your thoughts?


  • Alex

    Ok went to the vt consultation on friday. Turned out I have convergence insufficiency and accommodative insufficiency which I thought I’d had for some time now. I got the HTS home vision therapy system and am working with that now. Unfortunately though the program doesn’t come with the accommodative flippers you need for accommodative rock so I don’t know what I’m supposed to do for that. Right now I’m doing vision shifting where you look at something close and then at something far. Do you have any ideas on what else I could do for that?

    What I like about the program is that it’s the same type of thing as the magic eye books for convergence but they get progressively harder the more you get right which I think is cool. Will have to see in the coming months how much it helps out… if it doesn’t then I’m going to have to seriously consider in-office vision therapy to remedy this problem.

    • Call the office and let them know that you need the flippers. It should only take a couple of days to get them in. I truly believe you have found the best solution. Now you just have to be patient and continue the exercises. I’m going to respectfully step away as far as giving advice in relation to your training because I don’t want to contradict or interfere with the doctor you are working with now. Most people don’t find this option and don’t know that it’s available. The hard part is sticking with it because there is no microwaveable fix for your eyes. Best of luck, Alex! Keep me informed of your progress.

  • Alex

    Thanks Dr. Deviney I already went and got the flippers from the office so I’m using them now. It’s going to be a few months of doing these exercises before I evaluate the progress but I’ll keep an update.

    Thanks for your help

  • So Alex, what’s the latest?

  • Alex

    Hi Dr. Deviney,

    Been doing HTS home vision therapy program since august. I’ve noticed improvement in the condition but not anything 100%. I recently went back to the vision therapy optometrist a couple weeks ago and he measured my sight again. He said that my accommodation has improved a little bit, my divergence has improved, but my convergence hasn’t improved very much. This doesn’t make much sense to me considering when I first started the program I was only getting scores around 35-40 BO. The goal on the program that I read was 35 BO if you’re familiar with what I’m talking about. The 35 just represents how far the targets are away from eachother on the screen.

    Anyhow I’m getting 25 BI and 79-97 BO right now on two different procedures I’m doing (jump duction and regular converegence/divergence stereograms). I still feel a lot of pulling in my eyes for lack of a better word and aching. Noticed more double vision as well over the course of time but I’m wondering if my divergence has actually gotten better than my convergence so my eyes are trying to pull out even more. I was going to focus solely on convergence for the time being to see if that helps more.

    My insurance doesn’t cover office therapy which I was quoted at 5000 bucks so this is my only choice and I’m going to keep sticking with it. Do you have experience using this program? I do feel like I’ve made progress but I’m not going to give up until I’m close to cured. I just don’t know how much longer I should do the program.. I finished auto mode in the regular amount of time (around 16 weeks) and I’ve been doing it still ever since. So right now I’m on about 4 months or so but I still don’t feel like I’m close to finished. Do you have any advice? The doctor that prescribed me the program doesn’t really know anything about it.

    Thanks for your help and sorry for the late response. I didn’t get your message as a notification in my email for some reason.

    • My advice is to stick with it. You’re doing the best you can do considering you’re not able to get in any in-office therapy. Keep in mind that your divergence always has been better because that’s what your eyes naturally want to do all the time anyway. The exercises should make you tired. They are designed to be more demanding than normal activities so that normal activities become much easier. I have a working knowledge of the HTS software. Most of my patients have trouble completing it without the in-office therapy, so you are doing very well to keep yourself motivated to this point. Keep it up!

  • Alex

    I’d email you the above post but I lost your email when my account closed for school. Is it anywhere on this site?

  • Alex

    One more thing.. are you still using prisms in your glasses to help with computer eye fatigue?

    • Hi Alex. Yes I am wearing my glasses with prism right now. I will take them off when I go see patients. I haven’t forgotten your earlier questions but I just haven’t been able to catch up on all sorts of things. I’m sorry about that. But look for a response ASAP. Thanks for the updates!

  • Alex

    That’s perfectly fine I’m glad you respond to these questions they’re motivating and helpful. After 4 months of doing the program I’ve been teetering on whether I should continue doing it or not but knowing that sitting here and doing nothing about it isn’t going to help I’m going to continue on with it. The only reason I said that is at some points I felt doing that program may been doing more harm than good but then I realized that I had this problem way before I ever used this program so that can’t be it.

    The big motivating factor for me is pain obviously which makes it a lot easier to continue with the program. I was a bit confused because I finished the auto mode of the program in 2 months like normal but I know I’m not close to being finished with it yet. I still get pulling sensations in the eyes and intermittent double vision.

    When you prescribed this program for patients, did they ever say anything about doing convergence exercises making them have more double vision/pulling sensations? I have noticed more of that since I started using the program (I’m guessing due to the high intensity of the exercises and just overall fatigue). Since my divergence is now stronger, I’m going to focus solely on convergence exercises for a while and see what happens. I think more of the double vision might be stemming from the fact that my divergence improved and my convergence has relatively stayed somewhat the same since my last doctors visit which was about a month ago.

    I’m thinking that doing divergence for 7 minutes combined with doing convergence for 7 minutes might have been counteracting since my divergence was already decent.

    Thanks look forward to hearing your thoughts

  • Alex

    Oh one thing I forgot to mention (don’t know if I did or not already). The doctor prescribed me glasses back in august with +.37 sphere in both eyes with no astigmatism correction. He specifically didn’t prescribe astigmatism correction for some reason. I’ve also never seen +.37 sphere before either. As you know when I put them on it doesn’t look any different than when I have them off but he said they would help with my accommodative insufficiency.

    Previous times when I went to doctors they prescribed +.75 in my right eye and +1.00 in my left eye with astigmatism correction. I have a slight farsightedness in my left eye which I’m assuming there is +.25 more than the right.

    Perhaps the older prescriptions were too strong for my eyes I don’t know. Just out of curiosity I’m going to see a doctor in early February that has a Prio tester that might shed some light on what my eyes are doing at the computer. I’m still convinced though that 95% of the eye strain is from binocular vision problems and then the rest is the accommodative insufficiency because these exercises have helped more than anything else.

    • I do recall you mentioning your questions about the prescription differences that you have. Without seeing other findings from your exams, I can’t accurately comment on that. I have no experience with the Prio. Let me know your impressions of that visit.

  • Alex

    Sorry about that I forgot I asked that earlier. I did send an email over with a pic from HTS did you receive it? I just had a question in there about it. I’ll post after I go get the Prio test done to see what how it differs from the card test. The only reason I’m going is that its simulates pixels on a computer screen so maybe that could point out some clues of whats going on. Thanks for the replies.


  • Alex

    Hi Dr. Deviney,

    Is there a reason why you chose to use 2BI prism in your glasses instead of something like 4BI? Wouldn’t 4BI provide more relief from strain of the convergence muscles since it’s pointing your eyes even more straight ahead?

    • For everyone, there is a point when you can put too much BI prism in front of the eyes and it causes double vision. Then the effort to try to make it single vision again is way too much strain on the eyes. The ultimate end point for a pair of glasses is clear, comfortable binocular vision. I do have a total of 4 BI when you consider that I have 2 BI in front of each eye.

  • Alex

    I have the same 2BI for both of my eyes. I did notice one thing with my left eye prism.. it shifts the image to the left more away from the nose but also upwards as well. So it shifts the image up and to the left instead of just left? My right eye shifts just horizontally to the right. Is this normal or do you think these glasses might have been made wrong?

    • That could indicate that the lenses may be off a little bit. Sounds like vertical prism has been induced in to it. You should get that checked out.

  • Alex

    heh guess i won’t be wearing those anymore then. what happened was i had another pair of lenses made and they threw out my original lenses that had prisms in them. When they remade them they must have screwed it up and induce base up prism and base down prism in the left and right lenses. by the way did you recieve those other emails i sent about the pictures of the program?

  • Alex

    Hi Dr. Deviney,

    This is in regard to prism glasses again. I’m trying to get used to wearing these for computer use but I’m having a difficult time due to a pulling sensation I feel whenever I wear them. It feels like both of my eyes are pulling or feel tight when I look through them. Did you experience this when you first wear prism lenses and it went away or is there something off?



    • My eyes felt a little funny the first day or two, but it didn’t take any longer for me to adjust. The prism should make your eyes feel more comfortable. In my opinion, if they don’t, then something needs to be adjusted.

  • Alex

    Yeah most likely these glasses weren’t made right so that might be it. What I might try to do is get glasses made with the PRIO correction and prism in them. As far as the program goes, I went for about a week and a half without doing just as an experiment and my eyes haven’t been feeling much better still have a lot of that pulling sensation which I know is associated with CI and/or not adjusting to astigmatism glasses. Considering I get the pulling without wearing the glasses though tells me its more a muscle issue than anything. Did you recieve that email I sent a while ago with the results from the HTS program? It’s perfectly fine if you don’t want to review those I was just curious to see what your opinion was of them. I mentioned in that email that the picture I was showing was not from the divergence exercises but from the convergence one.

    The results may not show the whole picture though… just because I have more than adequate convergence ability doesn’t mean I have good sustainable convergence. I’m thinking of it like a sprinter.. can run really fast for short bursts but endurance no way. I’ve actually been focusing solely on convergence now just to build up that endurance that I need. I’m very interested in hearing your opinion on this but I do understand you’re busy and everything so its cool.

    • Just reviewed those emails…The base out ranges are certainly impressive and looking at that test alone sure does make you think you would be okay by now. But you’re right in that sustaining the convergence seems to be the most difficult thing for your eyes. You should be fine if you focus solely on convergence, but the jump ductions are good because it helps to make sure you can make a fluid transition from convergence to divergence and vice versa. What was your experience with the PRIO testing?

  • Alex

    I thought the same thing looking at the scores because it doesn’t make sense. I know people who can’t even see magic eye pictures in 3d because they don’t have great binocularity yet they aren’t suffering like this. I just did convergence alone for the last two days and today I noticed a lot more of the pulling sensation in my eyes. I’m guessing its probably making the problem worse.

    I think my positive fusional vergence ability is pretty high now and my near point of convergence doesn’t break at all not even right at the nose. It gets blurry at the nose clarity wise but I think thats normal if I’m not mistaken. One thing I did notice in my last exam was that during the NPC test when my doctor pulled the object away from my eyes (he was using a metal rod with a ball on the of it) the object went double and then came back into one. Not sure why this is maybe thats why he diagnosed me with CI. The fusion doesn’t break at all coming at my nose but when he went all the way to my nose and then pulled the object away it went into two images. I don’t know if this means anything or not just thought I would bring it up.

    I haven’t actually gone to the prio doctor yet I go on Feb 5th so I’ll see what comes of that. I’m really curious to see what my resting points of accommodation and vergence are though because maybe that will tell me something.

    One other thing I’m trying is moving the monitor a little closer to my eyes. I know this might sound stupid especially regarding my symptoms but I usually keep the monitor at 35 inches and I’ve actually had it all the way out to 52 inches before by enlarging the screen time. Neither way seemed to make a difference to my comfort level by pushing it back and when I was younger I never had it that far away. Just another experiment I guess

  • Alex

    Did a little bit of research on these scores and came across this line from the book “Clinical Management of Binocular Vision“. The authors say:

    Discontinue this therapy technique when the patient is able to achieve clear single binocular vision with 40 to 50 baseout and 10 to 15 base in. I think I’ve been way overdoing it for quite a while if this is right since my baseout score is 100 and my base in is 27. I’m thinking I might have been putting a lot more strain on my eyes than necessary for computer work. I just looked at my really old scores from August 20th of 2010 and when I started the program I was doing 35 base out. So I started out at 35 and now I’m at 100 and the doctor I saw said he didn’t see any improvement in convergence. I stopped doing the convergence exercise like 3 days ago and I still have bad pulling sensations in both of my eyes probably because I way overworked them. Sorry these posts are so long

  • Alex

    Hi Dr. Deviney,

    Just giving an update of what happened at the doctor today. Sorry my last posts were lengthy kind of just jotting down my thoughts. The Prio test really didn’t determine much except that my eyes do accommodate at the right distance for the computer screen. However the doctor did find out that I do have a significant exophoria at near just like the vision therapy doctor concluded. I believe these were the results:

    6 diopters of exophoria at distance and around 20 diopters at near. Like you noted he said my eyes just sit further out than most people’s and the constant stress of turning them back in is what is causing all of my eye strain. He did say doing the convergence exercises helps keep up fusional amplitudes but it doesn’t correct the alignment problem itself. So even though I have really high scores on the computer program I still have to use more effort than normal to turn my eyes in which is why the problem isn’t fully corrected.

    He said to keep the fusional vergence amplitudes up, and he also prescribed a new pair of glasses.

    OD +.75 4 diopters base in
    OS +1.00 -.50 axis 4 4 diopters base in

    So he gave me more base in, reduced the astigmatism and changed the axis, but kept everything else the same as my last prescription by correcting the farsightedness in my eyes. I guess it just sucks that theres no way to correct the alignment problem of my eyes because thats the root cause of this whole thing.

    • Interesting adjustment on the prism amount. I hope you feel an improvement in symptoms once you adjust to it. Keep me posted.

  • Wes

    I had terrible problems with headaches, eye muscles feeling like they were about to pop off they were so fatigued, mind fog, body numbness, etc. I went to a specialist and got a vertical prism .5 in each eye (my right eye is higher than my left). Also just a .25 in/out prism in both eyes.

    80% better now. Came across this site because I was looking at adding more in/out prism so maybe I feel fully normal (computer glasses). I sit at a computer all day.

    One thing I can tell you is most doctors would ignore the up/down prism of mine it was so small, but some eyes are more sensitive. Find a doctor that cares. Also the up/down prism has to be EXACTLY right for it to work. I noticed I can close each eye back and forth and you will notice the image seems to be higher or lower with each eye, so that might be a good way to tell.

    Hang in there guys. You’re onto the right thing, just have to find a doctor that’s really good and precise, and there’s only a few in the country (one in birmingham, MI).

    • Hi Wes,

      Thanks so much for reading and for your comments. You are spot on with all your comments, especially the vertical prism. I’ve found that can alleviate many symptoms. The challenge there is to find the best endpoint of vertical prism because that can be quite variable during an exam.

      Dr. D

  • Alex

    Hi Dr. Deviney,

    I’m doing in office vision therapy now for about a month so far. It’s scheduled for 12 weeks total so we’ll see where I’m at then. One thing that has been on my mind for a while though was the position of the monitor relative to the eyes. For instance I like having the monitor positioned lower than eye level (probably 2 inches lower) so I look downward when viewing it. For one the eyeballs are covered more by the eyelids for decreased evaporation and I just have been reading everywhere that this is better for your eyes visually because lower gaze angle is easier on the eyes at close distances. Is this true? I just want to make sure that looking downward all day isn’t making my eyes worse.


    • Hi Alex,

      I always recommend positioning computer monitors at or below eye level. For the reasons you mentioned, below eye level is more ideal. That slight downward gaze should not have much if any effect on your vision. A previous poster below, Wes, mentioned vertical prism and I have recently started asking more detailed questions in consideration of prescribing vertical prism. Questions include: History of motion sickness in a car or difficulty reading in a car? History of head tilt to left or right? History of neck/shoulder/back pain? I have also found that all of my patients with chronic pain have some sort of vertical deviation in their eyes. Wes refers to a practice in Birmingham, MI that I have found very interesting. The website is if you’re interested in getting more info.

      Thanks for the update. Dr. D

  • Alex

    Thanks for the quick reply. I’ll take a look at that website too. So as far as downward gaze goes, you recommended a slight downward gaze for computer use. Would a significant downward gaze be any different for the visual system that may make eyestrain worse? Lets say you had the monitor 30 degrees below horizontal eye level so you’re always looking down at the monitor no matter what. There’s just a lot of conflicting information about monitor height and downward gaze angle and was wondering if more than a slight angle is still fine for the visual system.

    • Hard to say if your eyes, specifically, would be strained more in downgaze without doing something like a cover test in downward gaze to see if you have more or less exo or esophoria or if it induces some sort of vertical imbalance while gazing down. Some desks have been built so that the monitor actually rests below (or within) the surface of the desk top itself. Have you ever seen one of those?

  • Alex

    Hi Dr Deviney,

    Yeah I guess I would have to get the cover test to see if it makes a difference. I just talked with the vision therapist today (and the other vision therapists in the office) and they all said that a strong downward gaze isn’t good for the visual system. I think its probably better to keep my monitor at eye height or just slightly below rather than what I have now. Right now my monitor at work is 4 inches below eye level so my downward gaze is pretty significant. I do this for two reasons: first I thought convergence was easier for the eyes in a downward gaze and second I thought that looking down covered a lot more of your eye from drying. I got this info from the people who make the desk you referenced. They’re called Nova or something like that and they make desks with monitors below the surface that are angled up and then you have to look really far down at them unlike the traditional way of looking at the monitor on top of the desk.

    Really hard to get a solid viewpoint when you have conflicting information like that on the net. What do you think? In your personal opinion do you think its better for the visual system to have just a slight downward gaze rather than a significant one for both of the problems I suggested? Thanks again for the responses.


    • I don’t have a solid opinion on the downward gaze question. At least nothing backed up by textbooks, journals or even my patient experience. I can only say that I personally feel that MY eyes are more relaxed when I look downward. I don’t necessarily believe there can be an unwavering opinion because each person’s eyes want to rest in their own unique positions/directions.

  • Alex

    My question was more geared towards how much of a downward gaze to have rather than if you should use a downward gaze. Most resources recommend like 10 to 15 degrees downward gaze (slight). Here’s one resource that suggests that:

    But then theres another school of thought which I don’t really believe is very credible anymore.

    I was using the advice from the ankrum site has a basis for how I look at the monitor believing this was the better way. However I recently found out that Ankrum works for Novadesk which you guessed makes the desks where you have to look in this downward angle to see the monitor. Since they have a financial gain to be had with this info and this is the only resource I can find suggesting this much of a downward gaze its more credible that the slight downward is better. Slight downward gaze is suggested on many sites including OSHA. Also the vision therapists suggesting that looking downward that much is bad for the eyes makes sense. I don’t think there is a natural act where you look at something at a 35-45 degree angle for 8 hours.

    • Thanks for the links, Alex. It does make sense that excessive downward gaze could have negative effects on the neck and shoulders. No surprise that the company promoting the lower gaze would also be selling those desks.

  • Alex

    No problem. I understand the implications to the neck and shoulders but you don’t think it would have negative effects on the eyes to look at an excessive downward angle? The only reason I’m asking this is personally I like to have the monitor below eye level. I feel like its more comfortable that having my gaze stare directly into the center of the monitor. I haven’t heard anybody else recommend that except for the vision therapists that I see every week. They all think that staring straight ahead at the monitor is better for the eyes than looking downward at it.

    I mean I guess everybody is different I just want to make sure I’m not causing more pulling sensation by looking down too much. Is there a limit to how much you should look down at something like the computer monitor? Slight gaze versus excessive gaze?

  • Neil Watson

    Hi there,
    What an interesting article. I’ve been given glasses with prism, 3 base out in each lens. However, I think I need more…

    When I do the lining up test, I see two boxes, let alone, misaligned lines.

    In the test I get things lined up and then the optician gets me to read a chart whilst reducing the prism all the while. At the end if this I saw the machine was set at 5 prisms each eye.

    So, I believe to line up properly I need something like 8 prisms each eye. Will 3 be enough do you think?

    Also, is 3 a little or a lot?

    Many thanks

  • OldFuddyDuddy

    I’m going to calculate three pairs of single-vision glasses (distance, computer, & reading) from one progressive prescription. I know how to handle the Spherical power (in some cases including contributions from ADD ) and the astigmatism correction. But what do I do with the prism numbers? I have 4.0BO and 2.0BD prism for progressives, and this also seems correct for my distance single vision glasses. But what should the prism values be for my computer single-vision glasses and my reading single-vision glasses?