Heterochromia refers to a harmless genetic anomaly resulting from an uneven distribution of pigment within one or both eyes.

Medically reviewed by Johnstone M. Kim, MD Of the four main eye colors (brown, blue, green, and hazel), the rarest eye color ...

Our muscles work in harmony, twitching and pulling fibers in perfect coordination. While some align in straight lines for ...

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 ...

There are three different types of cone cells which produce colour vision. The amount of light entering the eye is controlled ... by the muscles of the iris.