If you cover your left eye with your hand and look around, that is how I have been seeing the world. Except that I don’t have to use my hand; my brain has been doing this for me. The term in the strabismus biz is “suppression”, and here’s a definition from strabismus.org:
…The most common causes of amblyopia are constant strabismus… If one eye sees clearly and the other sees a blur, the good eye and brain will inhibit (block, suppress, ignore) the eye with the blur. Thus, amblyopia is a neurologically active process. The inhibition process (suppression) can result in a permanent decrease in the vision in that eye that can not be corrected with glasses, lenses, or lasik surgery.
I spent my childhood patching my “good eye” (to avoid suppression) and wearing dorky thick glasses with an executive bifocal (we presumed this would help cure the strabismus.) Imagine my surprise when I heard my doctor talk about me + suppression about two months ago, at a typically agonizing eye appointment at the U of MN. (And there was even more surprise when I noticed on my medical records: L eye AMBLYOPIA. I had no idea.)
I was compelled to make an appointment and see those yahoos because the double vision I was experiencing daily was starting to drive me crazy. From what I remember as s a child, I would have double vision only when my glasses were off. You can imagine, then, as an adult (& two childhood surgeries later), I would be quite alarmed when this double vision was happening with my glasses. Sometimes at night, watching TV, it was so annoying I’d have to close my left eye.
At this appointment, my doctor said something like, “well, when you’re suppressing, then you don’t have that bothersome double vision, so if you can do that, you won’t have that neurological piece bothering you.”
“That neurological piece”…when I heard my doctor say this last November, I thought this was an amazing concept–first of all, I never knew my brain had been “suppressing” my left eye’s images this whole time, and that the suppression was keeping me happy by preventing double vision.
- I had strabismus, and if my glasses were the correct prescription, they would keep my left eye from being wonky
- this would then prevent double vision
- “everything was cool” because of my surgeries
- wearing glasses resulted in the straight eyes I saw the mirror
And here’s my doctor, suggesting that I’m not using both eyes–just one–unless I am seeing double. Wow! What a giant surprise. I walked out of that appointment pleased with my new U of MN eye doctor (I’ve had two different MDs since Dr. Letson retired.) I even got a new prescription for some more prism for my next pair of glasses. Suppression! the apparent key to my visual happiness, according to Doc Bothun. I decided to accept this information and overall I felt good about my appointment.
He must’ve read John A. Pratt-Johnson & Geraldine Tillson’s advice on page 253 of their textbook Management of Strabsmus and Amblyopia: A Practical Guide:
An adult patient should be told about suppression and that ignoring the image from the deviating eye will not cause amblyopia as it would do in childhood. The patient should be encouraged to concentrate on using the dominant eye and to ignore the second image to encourage the normal process of suppression.
About a week after my appointment, I read Sue Barry’s book Fixing My Gaze, and I decided that suppression is actually not a cool thing, despite my MD’s nonchalance. I started to like my new eye doctor a little bit less, and I started to become quite disappointed in pediatric strabismic opthalmology as an entire discipline, the more I read Sue’s book…meanwhile my enthusiasm for and understanding of developmental optometry increased.
And I began to actually learn about my eyes’ capabilities and about strabismus, and this made me wonder if perhaps my double vision was actually a good thing. A symptom of a “lazy” left eye that still wanted to see, after all these years, after all that muscle-cutting surgery to yank it into place. When I see two images, that means my left eye is not suppressed. It means my eye is aimed in the wrong direction.
It’s my way or the high way. At this point I have learned a bit about suppression and also its “opposite” conditions: double vision or fusion. For normal people who see in 3D, their eyes are seeing two slightly different images coming into the brain, these two images are fused into one, and that normal person sees one image in regular-style 3D; they do not have double vision. But for me, when I see one image, I might be suppressing. My brain does not blend images well, because my eyes aren’t aiming well. My brain does not want two images of the fire hydrant, so it says, one will do…and left eye, if you are screwing around and providing a double image of the hydrant, you are banished! My way or the highway…shut out. Shut off. Done.
I will admit this idea is a depressing one for me, because obviously I need to have data coming in from both eyes for success with my vision therapy. But I am not hopeless about it–I just am fretting about it.
I think about that excerpt from the strabismus textbook, and I have to ask, is suppressing an entire eye “normal”? Perhaps the authors are confusing the term “commonly found within this population” with the idea of normal. At my high school, it was very common for students to eat lunch out of the vending machines…but does that make it normal? I hear someone’s mother, “if everyone jumped off a bridge, would you do it too?!” So, “deviant eye”, it’s time for my brain to quit suppressing you, and learn to control your wonky roundness. No matter what the experts writing the textbooks say.