I lack stereoscopic vision, due to eye surgery in infancy & wildly different focal lengths in each eye (one is very nearsighted, the other farsighted).
I can still see in 3D because my brain uses tricks like relative object size, shadows, and sometimes I move my head laterally so my farsighted eye gets different angles on an object (“faking” stereoscopic vision with one eye).
Nonetheless, catching a ball thrown straight at me is very difficult— I have to judge the size at which the circle is getting larger, and know the actual size of the ball. It often hits me in the hand and I try to grab it before it bounces away.
And I can never see those stereogram images where it looks like static unless you focus both eyes at some distance. I never see the world with both eyes simultaneously.
I once got glasses that corrected my vision “perfectly” but got major headaches and couldn’t wear them. Objects were in focus in both eyes, but were wildly different sizes!
I went to an ophthalmologist who basically told me they can correct my lenses but in my brain “the wiring is shot”.
I mostly work in front of a computer screen. I now use reading glasses so that when my nearsighted eye gets tired, I can put them on and continue working with my farsighted eye. These glasses have only a minor correction on the nearsighted eye so they don’t give me headaches.