One of the things we look at when we dilate the eye is the optic nerve cupping. It’s the white area in the middle of the optic nerve in the photo below. The smaller the white area the less the risk for glaucoma. As pressure damages the optic nerve, the white area grows and your peripheral vision decreases until you’re blind. The 2nd photo shows an eye with glaucoma. Note the absence of pink area inferiorly.