Fig. 3
(modified from [22])
Eye development and degeneration. Right: surface fish eye develops with a normal lens (l) and retina (r) and no apoptosis. Left: cavefish eye begins to develop with a small lens and optic cup with a gap in the ventral portion of the retina, and later arrests in growth and disappears into the orbit. First the lens (arrowhead) and then parts of the retina (arrows) undergo apoptosis detected by TUNEL. Center: steps of eye development in surface fish (right) and eye degeneration in cavefish (left)