Word of the week: Iris
Welcome to our first Word of the Week where we explore a vision related definition, 'cos the science behind your peepers can be an interesting thing!
Your iris is more commonly referred to as your eye colour, but it does much more than look pretty. It's responsible for controlling your pupil getting bigger and smaller (and the light that reaches your retina). If you think about your eye as a camera, the pupil is the eye's aperture and the iris is the aperture stop.
The most common eye colour in humans is brown and true green eyes are the most rare.