The iris is a structure behind the transparent cornea of the eye. It has a circular opening called the pupil that changes size in response to the light level. Your pupils are usually the same size as ...

A 77-year-old man awoke with blurred vision in each eye. His vision had been normal the night before. He had no headaches, jaw claudication, or other symptoms of giant cell arteritis. He denied any ...

The eye's light-sensing retina taps different circuits depending on whether it is generating image-forming vision or carrying out a non-vision function such as regulating pupil size or sleep/wake ...

Our eyes do more than just help us see the world—they can also reveal critical insights into our psychological state. Changes in pupil size, shape, and reactivity can sometimes signal underlying ...