Anatomy and Function of the Human Eye

Cornea

Clear outer surface, can be damaged by infections.

Iris

Colored part of the eye, controls light entry.

Pupil

Black opening in iris, adjusts to light levels.

Lens

Curved internal structure, focuses light onto retina.

Conjunctiva

Thin lining covering eyelids and scleral surface.

Sclera

White outer layer of the eyeball, tough connective tissue.

Choroid

Middle vascular layer, supplies blood to the eye.

Retina

Light-sensitive inner layer, converts light to signals.

Optic Nerve

Transmits visual information from retina to brain.

Rods

Photoreceptors for peripheral and low-light vision.

Cones

Photoreceptors for color vision, concentrated in macula.

Macula

Central area of retina, provides sharpest vision.

Vitreous Humor

Clear gel filling eye, maintains shape and focus.

Ciliary Body

Muscle controlling lens shape for focusing.

Visual Pathway

Route from retina to occipital cortex in brain.

Lacrimal Apparatus

Glands that lubricate and wash eyes.

Eyelids

Protective flaps that close over eyes.

Eyelashes

Hairs that protect eyes from debris.

Light Waves

Electromagnetic radiation entering the eye for vision.

Nodal Point

Location where light converges behind the lens.

Inversion of Image

Image is reversed and upside-down on retina.

Fluid Pressure

Increased pressure can damage optic nerve in glaucoma.