has muscles that control the constriction and dilation of your pupils. "Trauma to the eye can cause damage to the muscles that constrict the pupil, which makes the pupil stay dilated," Mackay says.

In the laboratory, all test subjects were then also exposed to artificial light of different wavelengths (red, green, blue and white) and their pupil dilation was measured for comparability and ...

Certain medications and medical conditions, such as Adie syndrome and cluster headaches, can affect the normal function of pupils. The pupil controls how much light enters the eye. In low light ...