Visual hallucinations may occur in any patients with severe vision loss. Patients are often afraid to mention them for fear someone will think they are crazy. These are not psychotic hallucinations, but are related to the brain misinterpreting the distorted image. This condition is known as Charles Bonnet Syndrome and has been reported in the literature for over 200 years. It was first noted by Swiss naturalist Charles Bonnet on observation on his grandfather.
Depth perception is a very fragile visual function.
Any decrease in vision may disrupt ocular depth perception. Two full functioning eyes are required for ocular depth perception. Threading a needle and other skills that require depth perception may become difficult.