Anatomy How does the iris change the size of the pupil? Asked by arwen46 12 years ago 3/6/2013 2:18 AM Last updated by anonymous 12 years ago 3/7/2013 9:51 PM
The iris has fibers in it that attach to the ciliary muscles that control the pupi. When light needs to be adjusted, the fibers in the iris rotate and adjust the pupil accordingly.
