When I was 4 years old, I had corrective surgery for strabismus in my left eye. Although it was minor, my pediatric ophthalmologist said that surgery would produce the best long-term results for my vision and appearance. This is a picture of me at the age of 2 years old with my left eye displaying esotropia, which is a form of strabismus causing one or both eyes to turn inward.
Since the surgery, I have worn glasses or contacts to correct my pre-existing hyperopic vision. Hyperopia, or farsightedness, occurs when the eyeball is too short and the image focuses behind the retina, which is the opposite mechanism of the more common condition, myopia. Eighteen years later and I am still living a life unhindered by strabismus complications, except for one thing; I am “stereoblind.”
It sounds worse than it actually is because this is the only vision I have ever known. In high school, I shadowed a pediatric optometrist who told me that I never developed stereopsis due to the interference of strabismus at a crucial age of development. Stereopsis is the perception of depth using binocular depth cues, such as binocular disparity. The lack of stereovision has not affected my ability to judge depth because I adapted to monocular cues at a very young age (as I was later a softball catcher and played basketball).
The only downfall that I have experienced is the inability to use the red/cyan 3D glasses. Three-dimensional books, television shows, and movies that are viewed at home with these glasses are blurry because I am unable to use binocular disparity and free fusion to view a single image. Surprisingly though, I can clearly see the 3D shows at amusement parks in their full 3D capacity. I was never told how this is possible, but I believe that distance is the major factor involved. Because I am farsighted, my eyes optimally function when fully diverged, or separated, which occurs in the large theaters at amusement parks. However, when I watch a 3D movie at my house or look at a 3D book, the images are less than 10 feet away, causing my eyes to converge to some extent. This is my only guess for the reasoning behind my odd ability to see large-scale 3D shows and not other forms of 3D entertainment. It is interesting that people can “see” the same things, yet perceive them in a completely different manner that cannot be adequately described for those with vision disorders.
It’s weird and interesting that you have both stereo-blindness and Hyperopia, and I think that you’re right about that having to do with the inability to see 3D only sometimes. I also have hyperopia, and for some reason things like computer screens and texting are the worst, and I can’t concentrate on them for more than 10 minutes without glasses, so I’d imagine that Stereo-blindness would only make it worse especially when you need binocular disparity.
It’s especially interesting that you say how little it impairs your life, only because when we first learned about it in class I imagined someone would be very impaired and need different glasses and the whole nine yards.