Vision Therapy, Stereopsis and Seeing At Night

I gave up driving at night many years ago — I simply could not see properly, and it seemed to me that I often saw things that were not there, or mistook vague shadows for the wrong objects, which was unnerving at best and dangerous in more than one instance. As time passed, I simply designed my life around this lack of night vision and planned to be in before sunset unless I had someone else do the driving. It never occurred to me to ask a doctor what might be wrong with my eyes. Nor did any doctor ever inquire as to why I could not drive at night, even when I said as much…It seemed to be simply accepted and acceptable to all, that I, starting at age 35 or so, should be unable to see well enough to drive when it was dark. Perhaps because I was already disabled and unable to work this seemed relatively unimportant to them, perhaps because I was a psychiatric patient it seemed to them somehow “reasonable” or understandable…Or perhaps because I myself showed no particular distress, only acceptance. But this was later not the case, and yet still the MD eye doctors remained aloof and uninterested, dismissive, as indeed my ophthalmologist largely was about my double vision when he couldn’t solve it immediately. It was only when I spoke to my optometrist friend, L, that I felt taken seriously. Not only did she immediately tell me to come see her in the office, that we would get to the bottom of the problem, but once we did, she put prisms in my glasses then encouraged me to see Dr D for vision therapy, knowing how important the chance of regaining stereo vision was to me.

 

Be that as it may, as to my lack of night vision I gave up a great deal because of it. I used to be a folkdancer and for many years it was a passion of mine, but when I grew unable to drive at night I had to give it up. I stopped visiting anyone after dark if I couldn’t walk there and back and I did not even go to the movies or grocery shopping, except when the drive was extremely well lit and I was willing to take a chance.

 

Now let me jump ahead to vision therapy. After my eyes “clicked” into place that afternoon/evening and even more in the days that followed I began noticing details and even whole objects that I had not seen before. It seemed that because my eyes had not before resolved certain details, like the boundaries between a near object and the background, which (and I know this sounds weird) had always been just a jumble and confusion of lines, not a crisp boundary, they simply ignored them. What that boundary defined simply disappeared for me. So, for example, if I were looking at a group of objects against a complicated background, the background and the foreground would simply mesh and much of the “picture” would be lost to my sight, to my understanding. A  collection of plants sitting in front of a  messy bookshelf might defeat any attempt to resolve it into more than a mass of greenery and generic books. I would not have been able to separate the plants into distinct leaves on distinct plants nor distinguish one book behind all the greenery from another. The meshing of lines and confusion of background and foreground would have made it all impossible.

 

THis is very difficult to explain to anyone who has not had this experience. Indeed, I cannot recapture it for myself, now that I have stereo vision; I can only remember what I saw when I did not have it. Imagine you are looking through an aquarium window and you see dozens of fish snoozing in perfect rows. You can see the rows and sight down them, 12 fish deep, counting each fish and see that there is space between each fish. But without stereopsis there is no space, and the consequence of that is tremendous: Without palpable space, there can be no perceived division, no distinction between the fish either, so that you actually cannot tell how many other fish are there, nor count them precisely. You might know, somehow, vaguely, that there is a “mass” of fish, but to say exactly 12 would be impossible, unconceivable to you without stereopsis. In point of fact, you’d have trouble resolving the fish into anything but a vague notion of  a “mess o’ fish.” At best they merely overlap like sheets of paper, rather than sitting each in its own three dimensional pocket. At worst, you can’t tell anything more than that there are a bunch of fish in there. And I’d be hardpressed to say which was indeed worse.

 

So, once I had stereo vision, I finally noticed, in the sense that I literally could see the plant leaves, the fish and other things I hadn’t seen before. Another newfound aspect of vision was that the foreground became sharp when I focused on it, but the background blurred. I had heard about this phenomenon, but had never seen it before, wondered what people were talking about all my life. When “laser photos” were first shown at an exhibit on the New Haven Green in the early or mid  1970s, everyone was oohing and ahhing over the crispness, the lack of blurring of the background, how everything in foreground and background was so detailed…But I remember thinking, What is the big deal? I see that all the time. And I didn’t understand at all what they meant by blurring of the background compared to the foreground…It was all mumbo jumbo to me. Of course, since I didn’t understand, I simply remained mum about it. I figured, okay, maybe I didn’t get it, maybe I was too science-stupid to understand. I was in fact either an A student just out of high school science or a pre-med post-college student, but since I couldn’t figure it out, I simply chalked it up to my lack of intelligence and moved on. Had I understood the implications both of what I did and did not see, I might have happened upon the problem earlier in my life. (THough likely not a solution, since they were telling people at the time that stereopsis could never be regained in adulthood.

 

So, here I am, Jan 2009, newly stereoscopic, able to resolve details I could not before, seeing more of the world and even able to notice that the background blurs when you focus on the foreground, and I decide, maybe I’ll try to drive in the dark…just once. I don’t know why I thought it might be different, but I had the sneaking suspicion that I might resolve the darkness differently too.

 

I started up the car and waited for the lights to turn themselves on (so I wouldn’t forget to turn them off). Then with a little trepidation, I pulled slowly out of the well-lit parking lot. Immediately, I could tell the difference. For one thing the whole world seemed better lit now. I could see, well, details where before there had been only darkness, and confusing chiaroscuro. Streetlights defined things, rather than merely casting shadows onto them, and assisted my vision rather than merely making matters worse. I could see into bushes, could see branches and inside the hollows. Dark recesses, doorways became just that: recesses, doorways, and not just patches of darkness, black blurs to stump and confuse me. My sole difficulty lay with the headlamps of approaching cars — these as always tended to unnerve and “blind me.” I found however that if I concentrated on the road and the side of the road, I could see right through them, that they did not in fact blind me at all.

 

 I once was blind to much of my environment and didn’t even know it. I thought at the time I started seeing Dr D that all I wanted was to recapture the experience of beauty I’d gotten a glimpse of when mesmerized by tree bark — the reason I embarked on Vision Therapy (no pun intended). I never dreamed that I would gain so much more vision and so much more functioning in my life in the process.

6 thoughts on “Vision Therapy, Stereopsis and Seeing At Night”

  1. Doing brock string has given me slight labrinthitus, is this normal in early stage exercise?

  2. Hi Pam,

    Just thought Id respond to your comment here as well so others might read it too. Double vision should always be taken seriously, most especially a new unexplained case of double vision as it can have very serious causes — brain tumor, myasthenia gravis to name just two. Once a neurologist has ruled out anything like that (you should at a minimum also have an MRI of the brain) I’d encourage you to see a good optometrist as they are particularly trained to investigate double vision, something ophthalmologists do not always test for, in my experience. Vision Therapy also tends to be conducted by optometrists, should your double vision be amenable to this sort of thing and you wish to pursue it. But at this point I’d mostly advise you to see a neurologist and find out first of all what is causing, or at least what is NOT causing the problem.

    Additional note: My convergence insufficiency and exotropia or the tendency for my eyes to drift outwards first began to be noticeable to me as a difficulty reading, well before it progressed to frank double vision all the time…

    Pam W, writer of Wagblog

  3. I used to be able to read, but recently when I look at the written word I get two words. If I shut one eye I read just fine, but with both eyes open I go into a stare type double vision. Odd!!!

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