Glaucoma is a defect in the eyes where your optic nerve suffers through damage. The primary purpose of the optic nerve is to carry information from your eyes to the brain. You usually suffer from Glaucoma as a result of high pressure in your eyes.
The innermost layer of the eye that helps absorb light is the retina. It contains a light-sensitive cell and nerve that carries information from the eyes to the brain. Moreover, it has two-part rods and cones where rods control low-light vision and cones maintain bright-light vision.