Pupils are the black circles in your eyes. They gather light and bring it to the retina to form images. Typically, the pupils dilate, or widen, in response to low light so they can collect more light. Sometimes pupils will dilate for a reason unrelated to the levels of light in the environment. read more
Dilation, or widening, of the pupils of the eyes is normal in conditions of low light in order to allow more light to reach the retina. Medically, dilation of the pupils is known as mydriasis. Specific medications known as mydriatics are administered to dilate the pupils for ophthalmologic examination. read more
There’s a many reasons why pupils will become dilated. But eye trauma /iris muscle damage or iris nerve damage/ can affect pupil size permanently. Maybe you know David Bowie, a great musician in our era who passed away last year. His pupils are uneven and it’s because of he had fighting in his childhood and damaged his iris. read more