
Pupil Anatomy, Function, Size, and Conditions
The pupil is the circular opening at the center of the iris that controls how much light reaches the retina. It ranges from 2 to 4 mm in bright light and expands to 4 to 8 mm in darkness, according to the NCBI clinical reference on pupil size. Two opposing iris muscles govern this adjustment:Continue reading “Pupil Anatomy, Function, Size, and Conditions”








