Some animals accomplish this with a retractable eye flap. Others rely on their pupils. The circular pupil, because of the way the muscle bunches as it contracts, is the least efficient at closing ...

Inside the human eye, the retina is made up of several types of cells, including the light-sensing photoreceptors ... aimed ...

Researchers have developed eye drops that extend vision in animal models of a group of inherited diseases that lead to progressive vision loss in humans, known as retinitis pigmentosa.