PSY-3215 Lecture Notes - Lecture 9: Vitreous Body, Retinal Pigment Epithelium, Presbyopia
Document Summary
Lens: fine tunes focusing of the retinal image. When the lens is flat - less bending of light waves (things far away are in focus) The lens is yellow (not clear) - as we become older, the lens becomes more yellow. Vitreous humor: jelly-like substance in the middle of the eye that maintains the shape of the eye. You lose the ability to focus on close objects. Cataract: the proteins in the lens aren"t perfectly aligned anymore (they become tangled) which causes the lens to become cloudy and blocks light that comes through the lens. The very back is the pigment epithelium. Provides nutrients and takes away waste products. Stuck into the pigment epithelium are the photoreceptors. If you get a blow to the head, the photoreceptors can pop out of the epithelium - detached retina. The concern is that the photoreceptors will die. Scotoma: a functional whole in the vision. Mainly in the fovea (fovea only has cones)
