What is the difference between young eyes and old eyes, regarding the eyeballs?

Degeneration: Many differences. For example, the lens can develop nuclear sclerosis, a type of cataract that can blur vision and filter out blue light. These lenses can be removed surgically. The ability of the ciliary muscle to accomodate (to read up close) decreases with age - termed presbyopia - often accompanied by better far vision. Also, as the vitreous degenerates, a retinal detachment can occur.