Each part and its function is below:
- Sclera: the tough outer coat of the eye which protects it from mechanical damage
- Cornea: a transparent 'window' that refracts light directly into the eye and helps focus the image on the retina
- Iris: the front of the lens that controls the amount of light entering the eye
- Pupil: an opening that lets light through
- Retina: Inside a choroid layer, it's a light sensitive membrane with receptors called cones and rods (see below for more info on those)
- Optic nerve: a nerve that transmits electrical impulses with information to the brain to be interpreted
- Vitreous humor: A jelly-like substance that helps the eye keep its shape and helps refract light onto the retina
- Conjunctiva: a transparent membrane that keeps the eye moist by secreting mucus
- Lens: A biconvex structure that can change shape according to whether the ciliary muscle and suspensory ligaments relax/contract
- Fovea: Where the majority of rods and cones are found (not sure about this one)
- Suspensory ligaments: keep the lens in place and help control its shape so light can be refracted onto the retina appropriately
- Ciliary muscles: contract and relax to help control the lens shape
The eye has cones and rods in the retina. Cones detect COLORS and have high sensitivity to detail. There are red, green and blue cones. Rods are responsible for vision with low light levels and detect black and white only.
When objects are far away, ciliary muscles relax and the suspensory ligaments contract so the lens is thin. When objects are near, ciliary muscles contract and suspensory ligaments relax so the lens is fat.
Distant
Is
Thin
Near
Is
Fat
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