Writer Andrew Leland started losing his sight 20 years ago, when he was in high school, as a result of a progressive eye disease called retinitis pigmentosa, an inherited condition that leads to the deterioration of the retinas.
Leland first experienced it as night blindness, in which he was confused that everyone else seemed to see in the dark so much better than he did. Over the years, his disease progressed gradually. He's now legally blind, although he still has a narrow field of vision, which allows him to see about 6% of what a fully-sighted person sees.
