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.

Medically reviewed by Christine L. Larsen, MD Medications, trauma, and medical conditions can lead to abnormally small pupils ...

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 ... use the range of less complex light ...

Muscles in the colored part of your eye, your iris, then work to constrict or dilate your pupils, letting in more or less light as needed. 2. Medication "Certain medications can interfere with the ...

In particular, they found that the more a person's eyes dilated during the task ... was that the lowest performers on the ...

Neurologists shine light into the eyes of trauma and stroke ... when visual stimuli was more or less interesting, indicating a relationship between the pupil’s movement and cognitive state ...