Complex sentence: Optimal candidates for retinal implants have retinal diseases, such as retinitis pigmentosa or age-related macular degeneration, which cause blindness by primarily affecting the outer layer of the retina, while leaving the inner and middle retinal layers intact.
Split into simpler sentences: Optimal candidates for retinal implants have retinal diseases, such as retinitis pigmentosa or age-related macular degeneration. These diseases cause blindness by primarily affecting the outer layer of the retina, while leaving the inner and middle retinal layers intact.