aqueous

humor

A watery fluid that fills the anterior chamber of the eye.

blind spot

The area where the optic nerve passes through the retina & where vision is not possible due to the absence of rods and cones.

choroid

The vascular, pigmented middle layer

of the wall of the eye.

ciliary

body

Structure associated with the choroid layer of the eye that secretes aqueous humor and contains the ciliary muscle.

ciliary muscle

The structure that controls the curvature of

the lens of the eye.

cone cell

Color receptor located

in the retina of the eye.

conjunctiva

A transparent mucous membrane

which lines the inner surface of an eyelid.

cornea

Transparent, anterior portion of the outer layer of the eyeball.

fovea centralis

The region of the retina that consists

of densely packed cones and

is responsible for the greatest visual acuity.

iris

Muscular ring the surrounds the pupil & regulates the passage of light through the opening.

lacrimal apparatus

The structures that provide tears to wash the eye,

consisting of the lacrimal gland and

lacrimal sac with its ducts.

lens

Clear, membrane-like structure that is found in the eye behind the iris and brings objects into focus.

optic chiasma

Where the optic nerves cross over one another

and continue on to the primary

visual area of the occipital lobe.

optic nerve

Nerve composed of the ganglion cell fibers that form the innermost layer of the retina.

pupil

The opening in the center of the iris

that controls the amount of light entering the eye.

retina

Innermost layer of the eyeball that contains the rod & cone cells.

retinal

A form of vitamin A.

rhodopsin

Light sensitive biochemical in the rod cells of the retina; visual purple.

rod cell

dim-light receptor in the retina of the eye

that detects motion but not color.

sclera

The white, fibrous outer layer of the eyeball.

visual

accommodation

 Ability of the eye to focus at different distances by changing the curvature of the lens.

vitreous humor

The jelly-like substance that occupies the

posterior chamber of the eye which functions in holding the retina in place & providing nutrients to the retina.