a close-up cross-sectional image of an eye for study.

cornea iris pupil lens retina optic nerve aqueous humor vitreous sclera choroid macula fovea rods cones ciliary body zonules anterior chamber posterior conjunctiva corneal epithelium stroma descemet 39aph39 membrane endothelium disc visual acuity light refraction focus neural signals vision photoreceptors eye anatomy ophthalmology crosssection structure function retinal layers health diagnostic imaging examination pathway entry disorders processing physiology eyeball macro human