"Miosis" is a medical term that describes the constriction of the pupils. Learn its causes, symptoms, and how to treat it.

Pupillometry measures the size and reactivity of the pupil, the dark circle at the eye’s centre through which light enters. Typically, the pupil contracts and dilates depending on the amount of ...

That coloured circle is called the iris and the black spot in the middle is the pupil. This is the part of the eye that lets the light in. Lights out please! When it’s dark, muscles in the iris ...