The margin of error

Interestingly, my strabismus was developmental since the age of three but in a relatively short amount of time I lost many of my adaptations (suppression, strabismic ways of eye teaming) to cope with misalignment of the eyes. First my suppression gradually declined because of life style, i.e. overly zealous studying, and then the way my eyes moved and alternated was abruptly changed through eye muscle surgery. This left me without any reliable adaptation to deal with my abnormally developed visual system.

So the only option then, is pick up the pieces and start all over again. My visual system seems to act as a binocular system that was disrupted rather than a visual system which developed strabismically. It has no real inclination, or possibility for that matter, to go back to monocular viewing, alternation or any of its other former ways. There's a strong incentive to use both eyes, and it's constantly trying to do so, with varying rates of success. It's a binocular system whose inability to move its eyes accurately is cramping its style. Because of its poor handling, my case more resembles strabismus which was acquired later in life through brain injury than that of a developmental strabismic equipped with coping tools safeguarding functionality.

The level of spasticity or lack of control when it comes to eye movement is fortunately declining. It has been declining for some years and every improvement is a win. As can be seen in previous video posts, it's getting harder to spot there is any problem at all! However, automation is the goal, not merely the ability to execute the movements using disproportionate amounts of attention and energy resources.

Despite already increased accuracy and speed, there is still a considerable margin of error when it comes to my eye movements. I can not entirely rely on solid binocularity yet. It's either right or not right, and if it's not right you need to waste extra energy on correction which could have been used for observation and interpretation of visual input. Another issue associated with the continual trial and error, and the exertion it requires, is the build up of tension. Because of the lack of eye muscle control, surrounding areas of my body (face, jaw and gradually the entire body) start to tense up. The efforts to keep my left eye in check and attempts to keep up binocular performance will often result in jaw cramps on the left side and headaches. In order to avoid such an escalation it's recommended to allow for a margin of error and try to cut the visual system some slack.

What activities allow for a margin of error?

Reading vs General Navigation

Given this larger than normal margin of error, I prefer to avoid situations which require specific eye behavior.and do not leave much room for error. An obvious example of such an activity that requires precise and infallible eye movements is reading. There's a number of different ways to read but they all require impeccable eye movement control. That's why reading with audio back-up is much more agreeable with me. There's more room for eye movement error that way.

In contrast, the general observation of a road, square or real life situation can be done using an endless variety of eye behaviors. Some are definitely more effective than others but you can still get around.  For someone whose eye behaviors start looking deceptively normal such activities requiring an accuracy level of 'approximate' are starting to be fine. It's starting to get less overwhelming, less out of control. More ocular control will be very welcome over the upcoming year(s) but it's already quite manageable.

Driving is actually easier than walking or running because my body and head stay more or less in position, especially on a highway. Because the road and the mirrors are much larger than the words on a page while reading, and driving is less cognitively taxing, my current level of eye control is okay for driving. In fact, driving is pretty calming as it allows for staring and the use of peripheral vision.

Individuals vs Groups

The difference between reading, general viewing of scenes and driving is pretty straight forward. Here's something which might be more unexpected, or maybe not. Perhaps people without eye muscle palsy experience this difference too. Meeting with one person is a lot more taxing to my visual system than meeting with a bunch of people. I don't look strabismic anymore so it's not about  appearance. Meeting with one person just doesn't allow for much of an error margin when it comes to eye behavior. When talking to someone you have to look at that person. That's specific. It's likely you will have to hold your gaze steady but every once in a while you have to look away. The social situation dictates your eye behavior and your eye muscle control system better be up to the task. Most people I know and enter in contact with are aware of my vision issues and if I do act a little more peculiar than normal and start staring in the distance, I just explain. No biggy. Nonetheless, I try to keep up the eye contact dance. After all, it's good practice! It's also an important means of communication but you need the physical eye fitness to do it. 

When meeting up with larger groups, there is more room for errors in eye movement. You can just listen to the conversation and stare randomly every so often. Attention is divided and you don't always have to look at the person who's doing the talking. It clearly also depends on how familiar you are with the group. An entirely new group in an new environment is a probable overload. I will have trouble moving my eyes to explore and keep up with the new situation, people and environment, especially over extended periods of time. Not much room for eye movement errors in that case because you'll preferably need your brain to deal with the situation rather than an eye movement deficiency. You're losing attention to something that should be working automatically.

Factors that decrease the margin of error

Short term

When I'm going to do something relatively visually taxing, which includes many daily activities in varying degrees, you want to have me well fed and well rested.

I burn calories like you wouldn't believe and when I get hungry my accuracy diminishes and errors occur more frequently. So I'm eating a lot of the time these days as my appetite returned after a couple of very stressful years. This has a double benefit. It more or less keeps up my visual performance in the short run and makes me look less emaciated in the long run.

Naps seriously improve my vision. Even an half an hour nap will seriously improve my visual performance for the night. Don't be a hero, take naps.

Basically I'm just a baby learning how to see. Now we know why they too eat and sleep all the time.

Long term

Current practice consists of finding ways to allow a margin of error while slowly crushing that same margin as time goes by. Sometimes it is not possible to avoid situations that are too visually stressful. Then I do have to hurt myself by pushing it too far, resulting in tension and headaches. But by minimizing the time I exceed my limit and by granting the visual system relative rest, the comfort zone slowly expands.

Eye control and eye alignment should be invariable but is, in my case, all to often variable. Invariable and reliable eye movement control is a great advantage when executing bottom-up visual processing (taking in new visual scenes and observing them) and top-down visual processing (combining stored memories with what is seen). Virtually any human activity employs these kinds of visual processing. Therefore, I'm very curious about the dormant potential that might be uncovered as the rate of movement errors further declines. Stereo vision, for one.   If I ever want to live a 'normal', independent life, there's no other way but to keep working on accuracy, speed and stability of eye movement.


Eye movement control and the use of glasses for hyperopes

It's still frail and not ready to be stress tested, but it's happening. As my gaze gets steadier and the margin of movement errors declines, there is less need for my glasses. As vergence gets easier, I can focus more on the accommodation aspects of visual training. Seamless interaction and collaboration of vergence and accommodation is crucial to obtain a lasting end result in VT. As I'm farsighted (+2.5 in each eye) this evolution could have been expected. The glasses are more a way of avoiding fatigue and thus gaze instability than a way of providing better visual acuity. In fact, I often have to look over them to read things far away. As gaze stability is maturing I actually see better in daily life without the glasses. Ultimately they will just be reading glasses for near point work. Sometimes it even has a calming effect to take them off, even refreshing in a way. I'm still wearing them daily but every so often I let my visual system have a go on its own. Even though my glasses are rimless, it feels different not to wear them. I can believe people have an easier time seeing 3D without glasses or with contact lenses. Glasses have a way of distorting light and possibly binocular vision. However, I'm not going in heals over head... They are a useful anti-fatigue tool while I acquire more eye movement control. 

Some vision testing in front of the webcam

Inspired by Dr. Charles Boulet's article on the Cover Test, I myself felt like doing some testing in front of the webcam.

First you can see me doing some saccades, or jumping movements, going from one corner of my laptop screen to the other. I started off quite well but then my left eye started lagging and had trouble keeping up. This resulted in some double vision when looking at the right. I slowed down and paid more attention to remedy the problem. In order to reduce 'slippage' my left eye needs to improve its quickness of reaction and accuracy. This will be a key factor in acquiring stereo vision and reliable reading skills.

During the cover test my gaze seems pretty solid. In hindsight, I realize that I should have covered each eye for a longer period of time to see whether it would stay in place. Still, not a bad result in view of where I came from.

In this video I am testing my ocular movement ranges. This slow tracking of the object seems mighty fine. I still feel some strain on particular eye muscles and have to stretch them to the limit but the video looks nearly perfect. There are no obvious restrictions in movement anymore.

I must say it makes me very happy to watch myself performing so well on these basic tests. From the outside I almost look 'normal'. There's no way in hell the untrained eye could tell I've had manifest strabismus for the larger part of my life.

Not a hierarchy of visual skills but a proposed aid for vision testing sequence

Hence I have definitely graduated to the 'Convergence Insufficiency class'. I still have trouble reading, problems with fatigue and trouble keeping up consistent performance (especially while moving) which are common symptoms in 'milder' forms of binocular vision issues. 'Milder' binocular vision issues are still a pain in the ass...  Nonetheless, when talking about convergence insufficiency I often heard professionals say it can be  treated successfully in less than a year. God, I so hope that's true!

As we get closer to a resolution, it is only natural my strabismus became less visible from the outside and more visual change will happen on the inside. That idea is so exciting. The idea of effortlessly pointing your eyes and just being able to focus on what is seen. Can't wait!

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- You want more evidence? I'll give you some evidence right here.

A wedding without double vision

This weekend I attended a friend's wedding. I enjoyed it immensely. It was a reminder of the fact that not everything in life has to be a struggle. Not everything needs to be difficult. It's nice to see so many happy faces celebrating a joyous occasion.

During the last three years I have gone out of social circulation a bit. This is because I was suffering from all the symptoms you might associate with a severe concussion due to chronically untreated and mistreated strabismus. Social circumstances don't always bend to health and resting needs. It's weird to suddenly need to close your eyes to rest them or have to lie down so I prefer to avoid such situations. It has been hard enough to manage and explain my condition to my in house family. It has often proven challenging not to lose my nerve and get angry at their incomprehension of what is obvious, at least, to me. Certainly when thinking they could have avoided the whole thing by using their own brains. Sometimes Sartre is right. L'enfer, c'est les autres.

I also didn't socialize too often because it doesn't change anything about my peculiar problem, drains my energy and adds to the frustration. I simply have to 'do the time' while not bashing into the walls too much. I have been fairly successful at doing my recovery time without repaying, often unintentional, hurt with hurt. That's the best and most sensible way of doing it. I'm good at restraining myself from doing stupid things.

Still, life goes on.  Everyone else goes on to live their life and you have to start from scratch. While they get to have opportunities, jobs, weddings and babies, I have to teach myself how to read. The wedge has always been there, and I have done a remarkable job of covering it up, but in the end the truth remains. I don't possess the visual motor skills to do even basic reading. High intelligence and impeccable work ethic will only get you so far without those.

Meritocracy is dead. I felt as if whatever I do makes no difference and gets me nowhere in life. No wonder I didn't feel like socializing. I mostly felt furious and alienated. This is why, despite being a sociable person and having lovely friends, I was not always capable of being good company. The last thing I wanted to do is lash out at them for something that isn't their fault. They can't help the fact that they have what I want without even giving it a second thought. They can't help a whole series of ignorant, negligent and blameful people made me squander my youth and are still making me pay for their mistakes. However, irritation is natural when being locked in in your own body. Usually thinking about all this lost time and effort makes me want to throw up. Fortunately I have a good understanding of the situation now and know the only solution for me is to take my losses and build a better visual system.

This weekend I felt differently. It might be because I was able to get through the entire day without running into double vision or insurmountable exhaustion. This made me enjoy the day, the lovely people and the beautiful party. However, I think there's more to it. Even though I'm not exactly aiming for a 'normal' life, it must be nice to be able to function normally. In other words, take your life into your own hands. I think I can eventually attain that freedom. I'll have to work with the delayed time frame but I feel as if there's still hope for me after all. In a recent e-mail conversation with Sue Barry, she told me: "It's amazing how much we were missing visually, but this also gives us the opportunity to keep improving. Although my biggest visual changes occurred when I was in formal therapy in 2002 and 2003, I still strategize with my optometrist a few times a year about new exercises I can practice at home, and my vision continues to improve. I'm 60 years old, and while all my friends are complaining about how they are aging, I'm seeing better. So, there are compensations and -you're right - the best is yet to come."

Being there I could just savor the moment without feeling betrayed by anyone having had 'an easier time' than me. I could be happy for them without thinking about our contrasting lives. I won't have to be a dysfunctional illiterate person without opportunities forever. I too will be okay one day and get out of this mess. Among all those happy people I thought about how far I have already come in recovering the unrecoverable, enjoyed my single vision and smiled. Indeed, the best is yet to come.