Light enters the eye through the cornea, which refracts incoming light. Next, light travels to the pupil, which controls the amount of light entering the eye. From the pupil, light travels to the lens which focuses on the image and projects it onto the retina. The main role of the retina is color perception but it is also in charge of transmitting the image to the brain (National Eye Institute, n.d.). The retina also contains the cells known as photoreceptors that are responsive to any incoming light (Murray, n.d.). Specifically, the two photoreceptors in the human retina are known as rods and cones. Rods are mainly responsible for measuring color brightness whereas cones determine color (National Eye Institute, n.d.).
