It's made up of at least 10 ... with two sides that can close like a sliding door, is far better at this task, which is why so many nocturnal eyes have slit pupils. These apertures can be vertical ...

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.

An optician referred her to the hospital, where an MRI scan revealed what was thought to be a schwannoma tumour on her third ocular nerveCredit: PA The pupil in her eye had expanded so much that ...

it could be that your eyes aren't lined up. We shine it in the eye to make sure that the pupil is brisk and responsive to light then we will cross it back and fourth to make sure that they are ...

It's made up of at least 10 ... with two sides that can close like a sliding door, is far better at this task, which is why so many nocturnal eyes have slit pupils. These apertures can be vertical ...