Question

1st post:
I'm looking for advice relating to vision problems that I have been experiencing. I am not expert on the terminology, but will do my best to describe my situation. I hope that someone will be able to point me in the right direction as to how best to address my problem.
I am now 32 years old, and I have worn glasses since before the age of four. I've been diagnosed with esotropic strabismus. Over the past few years, I have been experiencing eye pain (eye strain?) in my weak eye. It often occurs when working at a computer, but also occurs doing other activities (driving, watching films, etc.).
When I was first diagnosed, my parents were opposed to eye surgery. I was prescribed corrective lenses and underwent vision training. During my elementary school years, I wore bifocals. At age fifteen, I made the transition to single vision lenses and underwent some additional vision training.
Throughout my high school and college years, I functioned well with my single vision lenses. However, I found that I had to give up activities such as drawing which required extended concentration on very close objects (especially when interspersed with focusing on more distant objects, such as the scene I was drawing). Whenever I attempted to draw, my weak eye would become unable to fuse the image after a few minutes of work, and it would turn in on me so that I was cross-eyed. I was able to read or use the computer for extended periods of time.
I also found that it generally took me 15-30 minutes in the morning to bring my eyes into a situation where they would work correctly together doing a closeup activity, such as reading. Occasionally (maybe 4 times a year), I would have a bad day where I was unable to get my eyes to focus/fuse nearby objects at all. Other times, I would become tired at the end of a day, and loose the ability to focus/fuse nearby images.
I moved across the country (to California) and eventually changed doctors, so that I would not have to travel 3000 miles for an appointment. My long time doctor was getting ready to retire anyway. I explained the above situation to my new optometrist, and he suggested that adding some amount of prism would help me. I was prescribed 3 b.o. in each eye and 1 b.d. in my weak, right eye. After some amount of initial effort, I was able to get used to the new prescription. This occurred in Oct, 1990. The following year, I returned to the office to find that this doctor was replaced by another. She determined that I did not need the 1 b.d., but decided that the rest of my prescription was similar enough, so that I could continue with my current glasses until I was ready to buy new pairs (sunglasses, regular, and backup).
In spring of 1993, I updated my prescription. After a few months, I found that I started experiencing eye strain when working at the computer for long hours. I visited my current optometrist as well as my long term doctor, across the country. Both agreed that my current prescription was correct. I found that I was often more comfortable with my older pair of glasses, so the new prescription was made to be similar to the old one (the axis had been a bit different) but without the 1 b.d. This did not help.
As the years past, I found that sometimes my eye would feel fine for a period of a month or so, but at some point it would always start hurting again. Over the past four years, my prescription has been determined by a number of doctors, and it is always very similar. However, my eye pain / eye strain as increased. I describe it as feeling that my weak eye is forced to work hard in order that I see clearly. Recently, I have been prescribed +1 progressive glasses for computer use. These seem to help somewhat; however, they are a bit difficult to use as part of my large computer monitor is always a bit blurry (I may try a single vision version instead). Unfortunately, I still experience problems when not using the computer or doing near distance work. I just completed 10 weeks of vision training, using both computer based and more traditional training aids similar to what I remember from 15-20 years ago. I believe that these have improved my ability to see out of both eyes and to properly fuse images. However, it has not succeeded in helping with my eye pain.
So, what do I try next? The eye pain is intense and continuous enough that it interferes with my daily life. Is my situation unique? My doctors don't seem to have encountered a similar problem. Here is my current prescription:
Sphere Cylinder Axis Prism
+2.50 -1.75 096 3 Out +1.75 -1.00 073 3 Out
I live in San Francisco, and would welcome a specific recommendation if that is appropriate. I would also welcome pointers to specific pieces of literature.
Thank you for you time. I hope that I did not include too much extraneous information. Let me know if you require any additional information.

2nd post:
I have been experiencing eye (muscle?) pain for the past few years. I have strabismus (esotropic). The discomfort is often present in my weaker eye and only exists when using it in conjunction with my stonger eye. If I cover my strong eye, my weaker eye does not experience pain.
I have had prisim in my lenses (3 b.o. each) for the past 7 years. For the initial 3 years, I also had 1 b.d. in my weak eye.
Is it common for someone with my problems with experience pain/discomfort? What can I do to resolve the problem?
I've recently tried vision training, which does not seem to help. I'm also trying computer glasses (+1), which seem to help while using the computer, but this is not the only time that I have discomfort.
My doctor suggested that I might want to use a weaker lens in my weak eye (it is not corrected to 20/20) so that it would not work so hard in conjunction with my stronger eye. I assume, with some reduction of overall vision.
Any other options?
Could it be related to the 1 b.d. that I had for a number of years? A variety of doctors agree that I don't need this prisim. Could I have gotten used to the prisim so much that it is a problem for me without it even if it doesn't appear to be a problem during testing? The discomfort in my weak eye is as if it is working very hard to fuse/focus on an object. It almost feels as if a stronger lens would help it to relax a bit. But again, testing indicates that I have the correct strength of perscription.

Additional information supplied:
As I have previously stated, I have been experiencing discomfort in my weak eye during the past four years. The general sense is that my weak right eye is working hard to see clearly and match the image to my stronger left eye. I find that this interferes with my daily life and am hoping to find a solution. I'm hoping that you can recommend a way to proceed. You'll recall that I currently have 3 b.o. prisim in each lens. In the past, I also had 1 b.d. in the right lens. All doctors agree that I do not need the 1 b.d. in the right lens. Since I was having troubles, a doctor agreed to check again and found that I needed 1 b.d. in the left (not the right) lens. I've been trying that recently, but I don't feel any better (and may feel a bit worse). Two different doctors in the same office agree regarding the 1 b.d. in the left. Can this change over time? That is, I used to need 1 b.d. in the right, but now I need it in the left? I've also tried some vision training exercises, but they do not seem to help my problem (I tried for two months).
While at work (using the computer), I have some near distance glasses. These have an increase in perscription strength of +1 in each eye. That is:
+3.50 -1.75 096
+2.75 -1.00 073
instead of
+2.50 -1.75 096
+1.75 -1.00 073
(they have progressive lenses -- so there is some distortion)
This seems to offer a fair amount of relief for me while using the computer.
However, as soon as I switch back to my regular glasses, my eye discomfort returns. I need a solution for daily use, not only at the computer. The doctors have made some suggestions:
1. Increase the prisim to 4 b.o. in each eye.
2. Decrease the prescription in my weak eye so that it blurs a bit and won't try to work with the stonger left eye.
What are my other options? Note that if I cover my strong eye, then my weaker eye feels comfortable. It is only when they work together that I feel discomfort (but, of course, I do not see so well with just the weaker eye). Is surgery an option?
Might I need a stronger perscription for daily use? Should I try 1 b.d. in my right eye (like my old glasses from 4 years ago -- when last I was comfortable) even though the doctors say that is definately the wrong perscrption for me?

(John Eisenman )

Answer:

Dear John,

Thank you for sharing your experience with eye strain with us. Your case is very interesting and has many sides. First, before I discuss the many reasons that may cause your problem, I should not forget to ask you what degree of binocular vision you have: are you able to see depth with two eyes, in other words, do you have full stereopsis ? Please let us know. In the wealth of information you supply really the two by far most significant sentences are that you were diagnosed as as having convergent strabismus as a child and wore bifocals. Apparently, an orthoptist diagnosed you as having convergence excess, i.e. the squint angle is much larger when looking at near thatn when looking at far. This is a life long problem that, in adolescence, tends to give the complaints that you have now: You experience eyestrain when looking at near. Whether complaints arise or not, however, depends primarily on the degree of binocular vision you have. There is no cure for convergence excess other than bifocals or a particular kind of surgery that is practiced more often in Europe than in the US: sewing the medial rectus muscles to the inner sides of both eyes, to prevent them from turning inward too much. Prof. Joe L. Demer, a good friend of mine and an exremely good strabismologist at UCLA (Jules Stein Eye Institute, 100 Stein Plaza, LA, CA 10024-7002) could advise you on that surgery. It works fine but, as I said, it is done more frequently in Europe than in the U.S. Alternatively, I advise you to have the strengths of the reading parts of the progressive bifocals increased to the point that computer work or reading causes no more problems. Like many you experience difficulties with the transition zone ("blurry aread") in the progressive bifocals and it may well be advisable to use separate reading glasses or long line bifocals. Secondly, the cylinder and the excess hypermetropia in the right eye may cause part of the problem, also very much depending upon the degree of binocular vison you have. If it were the only problem, glasses of various strengths and with various cylinders would have to be tried to see what gives you optimal binocular vision without causing eyestrain. I expect the convergence excess to be the major problem, however.

(Herb Simonsz, MD, PhD)

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