–written by anthony d’agostino
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If people truly had zero depth perception, how could they function? Everything could be like that game you play when you were a kid where you hold the moon in between your two fingers. Or that “Kids in the Hall” skit, where the guy looks through his fingers and says “I’m crushing your head!” and then he squeezes the people on the street people between his finger and thumb. But people can tell when things are distant or near..one eye or two
But there is more to depth perception that stereo-vision. Objects that are further away get lighter in color and can be hazier than objects that are closer to you. There are also differences in size and proportion.
People who see with one eye could learn to rely on these cues to a greater degree than those who use two eyes.
My exotropia was alternating and intermittent from the time I was 7 until my late teens when it became nearly permanent. I would always choose one eye or the other..and I kept the ability to pull them in for photographs or first meeting people.
When I did the binocular vision tests in the Ophthalmologist’s office, looking with one eye…the objects on the card did not pop-out at all. When I consciously pulled my eyes in prior to surgery…the letters and (in my case it happened to be) insects jumped off the card like a 3-d movie. It was at a hospital mainly for children..so everything was Elmo! and Finding Nemo..and cute animals and bugs!
For me…the difference between stereo-vision and monocular vision is: The front of a curved brown-stone building in Boston, is more curved. The texture of grass appears more “grass like,” and detailed. The shadows and highlights that help to illustrate the edges of textures is more evident. From my perspective, I am able to perceive more of the “aliveness” and “tension” contained in the object I am viewing when I am using both eyes. The variation in tones is more evident to me and the curvature of things.
I sometimes thought of my strabismus-vision as a string that was de-tuned. Sorry for the synaesthesic analogy, but when the string sounded..it was flat. After surgery…my larger field of vision seems to just “float” in front of me, more like a taut string, ready to resonate.
Maybe there are two headlights illuminating the distant object now instead of just one.