Is Bill Cosby blind ? why was Bill Cosby wearing Sunglasses on oprahs show

After seeing Oprah's show, me too was wondering like everyone else about the mystery behind Bill Cosby's cool sunglasses. He explained it to Oprah about the redness in his eyes and he appears to have good vision.

Considering the number of TV shows and comedy series that Bill Cosby has done and having been out in the studio lights, maybe he is a little sensitive to bright lights, that could be the reason behind the sunglasses, me thinks. He also appeared on Larry King's show with the sunglasses on.