Eye color depends on the iris ... action when it squeezes or relaxes to let in more or less light through the pupil. The iris is made up of two layers. For almost everyone - even people with ...

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.

These pupils are surrounded by a metallic gold or ... The combination of the vivid eye color and the gecko’s expressive gaze ...

(Interestingly, different animals have different color tapeta ... which is why so many nocturnal eyes have slit pupils. These apertures can be vertical, horizontal, or diagonal.

(Interestingly, different animals have different color tapeta ... which is why so many nocturnal eyes have slit pupils. These apertures can be vertical, horizontal, or diagonal.