Human Anatomy & Physiology: The Eye

sclera

tough, fibrous, white outer coat extending from the cornea to the optic nerve

retina

choroid

iris

pupil

the adjustable opening in the center of the eye through which light enters

optic disc

Blind spot on the retina.

cornea

lens

The cornea is avascular.

Why can the cornea be easily transplanted into a person?

vascular

Consisting of blood vessels.

avascular

Lack of blood vessels.

The dark middle layer contains blood vessels that prevents scattering of light

What does the choroid contain?

Tears help to lubricate your eyes and they help to keep your eyes clean and protected from irritants.

Why are tears necessary for the eyes?

smooth muscle

The iris is composed of _____________.

regulate the size of the pupil

The function of the iris is to _____________.

aqueous humor

Fluid in the anterior chamber of the eye.

vitreous humor

Fluid in the posterior chamber of the eye.

rods and cones

Photoreceptors in the retina.

fovea centralis

This is the highest concentration of cones in the retina and provides the point of sharpest vision.

It is the area where the optic nerve leaves the eyeball.

What is the reason for the blind spot on the retina?

hyperopia

farsightedness, focal point is BEHIND the retina

myopia

nearsightedness, focal point is in FRONT of the retina

emmetropia

normal, focal point rests on the retina

concave lens

What lens is used to correct myopia?

convex lens

What lens is used to correct hyperopia?

Nasoloacrimal duct

nasolacrimal duct (sometimes called the tear duct) carries tears from the lacrimal sac of the eye into the nasal cavity.

optic chiasma

The point at which nerve fibers from the medial side of each eyeball cross and go to the opposite side of the brain.

What are the Six Eye muscles ?

Cornea

the transparent layer forming the front of the eye.

Iris

Colored portion of the eye which is a muscle that Controls the amount of light entering the eye

Ciliary Body

Contains muscle that controls the shape of the lens

Lens

The lens is a transparent, biconvex structure in the eye that, along with the cornea, helps to refract light to be focused on the retina

Retina

Contains sensory receptors that process visual information and sends it to the brain