Photoreceptors<span>: The light sensing nerve cells (rods and cones) </span>located<span> in the retina. Pupil: The adjustable opening at the center of the iris through which light enters the</span>eye<span>. Retina: The light sensitive layer of tissue that lines the back of the </span>eye<span>.</span>
Explanation: The retina consists of two types of cells. They are rods and cones. These are light-sensitive nerve cells and carry the light impulse to the brain. Rod cells are meant for dark or light vision. Cones are dealing with color vision. Rods consists of proteins called rhodopsin and cones have photopsin protein.
