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 condition may also be present from birth. Pupils, or the black parts at the center of the eyes, change size to regulate the amount of light entering the eye. Pupils are large in the dark to ...

(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.

A new study reveals that pupil size fluctuates constantly during sleep, reflecting changes in brain activation levels.

pupil movement might one day be used to detect disorders such as insomnia and post-traumatic stress disorder, or even a comatose patient’s recovery. We haven’t yet figured out if eyes are ...

IN the past many investigations have been carried out on the static and dynamic reactions of the human pupil to illumination of the eye using white light. In this respect it seems surprising that ...