The peripheral drift illusion causes us to perceive motion in a still image. A new study shows that the mechanism of this illusion relies on changes in pupil size.

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

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 ...

Dilated pupils are also caused by drug use, sexual attraction, brain injury, eye injury, certain medications, or benign episodic unilateral mydriasis (BEUM). The size of your pupils can say a lot ...

Just admit it, goat eyes look weird! It's the pupils, mostly, but goats can also do things with their eyes that humans just can't. A study out of the University of California, Berkeley looked at a ...

In this Healio Video Perspective from the ESCRS winter meeting, Pavel Stodulka, MD, PhD, speaks about the role of pupil size ...