The Black Spot, or Opening in the Circular Muscle of the Iris

Question

The black spot, or opening in the circular muscle of the iris, is the _______.
A) iris
B) retina
C) lens
D) pupil

Accepted Answer

The black spot in the center of the iris is known as the pupil. The iris is the colored part of the eye surrounding the pupil. The retina is the layer of tissue lining the back of the eye that contains the light-sensitive cells necessary for vision. The lens is located behind the iris and helps to focus light onto the retina.