The vitreous is a gel that occupies the posterior compartment of the human eye
. The retina sends impulses through the eye to the brain and sends it back which shows up as the images that we see. The human eye size starts from eighteen millimeters during infancy to about twenty four millimeters at adulthood. There are three common refractive errors that many people get such as myopia, hyperopia, and astigmatism. After the age of forty some people are at risk to develop presbyopia. Presbyopia is a condition that makes it harder to see things up close rather than farther away.