01:830:301 Lecture Notes - Lecture 5: Optical Power, Ciliary Muscle, Optic Nerve
Document Summary
Sclera - hard, white, outer shell of the eyeball - main function is to maintain the shape of the eyeball. Choroid - where the eye gets its blood supply from. Retina - innermost layer, photoreceptors are found here, where the image is formed. Optical power = cornea ((cid:1152)) + lens ((cid:1151)) When the ciliary muscles are relaxed, the optical power becomes weaker. When the ciliary muscles are contracted, the optical power becomes stronger. Accommodation - when looking at far object to close object and vice versa. Eyeball too short or lens too weak. As an effect, nearby objects are blurred (rays do not converge enough) A convex lens would correct this to amplify the optical power. Eyeball too long or lens too strong relative to the size, depth of the eyeball. Distant objects are blurred (rays converge too much) A concave lens would correct this by weakening the optical power.
