The iris is the coloured circle that surrounds the pupil in the center of the eye. It is mostly made up of fibres of collagen protein and muscles. Collagen fibres are arranged in a specific fashion which is different between individuals, making each person’s iris as unique as a fingerprint!
Humans can have a wide range of iris colours such as blue, green, hazel and brown. Eye colour is determined by multiple factors such as the amount of melanin (the same pigment that influences skin colour) and the amount of light that the iris scatters.
Unlike the iris, the pupil is not a structure of the eye because it is just a hole which allows light to enter the back of the eye. The dilator muscle of the iris functions to make the pupil larger allowing more light to enter the eye while the sphincter muscle of the iris makes the pupil smaller reducing the amount of light entering the eye.
If you have any questions about your eyes or the health of your eyes, schedule an eye exam with our caring Stoney Creek eye doctors at Perception Eyecare. Call/text us at (289) 309-1090 or email us at [email protected]