Pupil

A) Photoreceptor cells that function in black and white vision
B) Photoreceptor cells that function in color vision
C) The opening in the iris
D) The innermost tunic of the eye
E) A pigmented contractile structure

Pupil

The opening in the center of the iris of the eye, through which light enters the eye.

Photoreceptor Cells

Specialized neurons located in the retina that are capable of converting light into signals that can be interpreted by the brain as vision.

Innermost Tunic

The deepest layer of a structure, often referring to the inner layer of an organ or tissue, such as the eye or blood vessels.