The condition he has is Keratoconus. This condition causes the cornea (outer dome shaped layer of the eye) to bulge out making a cone shape.
In patients with this eye condition, the collagen fibers protecting the shape of the cornea weaken and can’t hold its ideal shape. The cornea thins and begins to bulge. This will usually start in one eye and then progress to the other. It could start as early as childhood and progress slowly or rapidly.
The affected eye’s cornea may be so thin and weak that it may tear leading to corneal scarring. Progression of this eye disease causes double vision, halos around bright lights, difficulty seeing but rarely causes vision loss. Treatment of this condition includes eyeglasses, contact lenses and if severe, corneal transplant.
So what else could be occurring with his Bill Cosby’s eyes? To me, it appears the lens is cloudy and he probably is suffering from cataracts. This can also lead to poor vision. But even more serious than cataracts is glaucoma, a buildup of pressure in the eye that could eventually lead to blindness if it damages the optic nerve.
So if Bill Cosby has all three: Keratoconus, cataracts and glaucoma, he can certainly be suffering from failing vision. Although sometimes genetics come into play with eye conditions such as these, early and routine eye doctor visits are recommended to screen and manage them.