What is the black circle around the iris called?
The black circle around the iris is called the Pupil. The pupil may contract or dilate depending on the amount of light; it limits or increases the amount of light in the eye. Visit http://www.webmd.com/eye-health/amazing-human-eye, http://www.pasadenaeye.com/faq/faq15/faq15_text.html or http://www.99main.com/~charlief/Blindness.htm for more details.
the iris is the colored part of the eye that circles around the black pupil