Human Eye -Iris

Iris of the eye. Coloured scanning electron micrograph (SEM) of the inner surfaces of the iris and adjoining structures in the human eye. At far right (blue) is the edge of the pupil, the hole that allows light into the eye. Coloured mauve is the iris which controls the size of the pupil and therefore how much light will enter. The band of folds down the centre (red) are the ciliary processes. These secrete fluids that nourish neighbouring parts of the eye. (STEVE GSCHMEISSNER/SCIENCE PHOTO LIBRARY)

(Source: sciencephoto.com)