Maybe this is why some people, blind from birth, still cannot see (as normal seeing people do) when their ability to "see" (with the eye) is technically restored. The part of the brain that processes visual stimuli must be trained to do so from birth or it loses the ability to really "see."  The up side of blindness is that this part of the brain usually becomes devoted to doing something else better.

I can swear there ain't no heaven but I pray there ain't no hell. _ Blood Sweat & Tears