If evolution occurs through gradations, the critics say, how could it have created the separate parts of the eye -- the lens, the retina, the pupil ... different types of eyes have emerged ...

"Miosis" is a medical term that describes the constriction of the pupils. Learn its causes, symptoms, and how to treat it.

They also adjust how much light enters your pupil so you can see in ... nutrients to important parts of the eye, like the retina. There are four main types of uveitis, depending on where the ...

Nocturnal animals tend to have proportionally bigger eyes than humans do. They also tend to have pupils that open more widely in low light. So, at the outset, nocturnal eyes gather more light than ...