eye

Most of the eye is enclosed in a bony orbit

A cushion of fat surrounds most of the eye

eyebrows, eyelids, conjunctiva, lacrimal apparatus, extrinsic eye muscles

meet at the medial and lateral commissure

-Tarsal glands produce an oily secretion that lubricates the eye

-Ciliary glands are located between the eyelashes

membrane that lines the eyelids

connects to the surface of the eye

secretes mucus to lubricate the eye and keep it moist

conjuctivitst is inflammation of the conjunctiva results in red irritated eyes, caused by a virus or bacteria very contagious

inflammation can be caused by dust

lacrimal gland and ducts that drain into nasal cavity

produce lacrimal fluid, situated on lateral aspect of each eye

drain lacrimal fluid from eyes medially

provides passage of lacrimal fluid towards nasal cavity

empties lacrimal fluid into the nasal cavity

Protects, moistens, and lubricates the eye

Empties into the nasal cavity

dilute salt solution, mucus, antibodies, lysozyme

6 muscles attach to the outer surface of the eye and produce eye movements

these muscles are controlled by cranial nerves 3, 4, 6

ensor-Layers forming the wall of the eyeball:

fibrous layer

outside layer

vascular layer

middle layer

sensory layer

inside layer

humors are fluids that fill the interior of the eyeball

sclera and cornea

• White connective tissue layer

• Seen anteriorly as the "white of the eye"

transparent, central anterior portion

allows for right to pass through

repairs itself easily

the only human tissue that can be transplanted without fear of rejection

choroid is a blood rich nutritive layer in the posterior of the eye

modified anteriorly into 2 structures

smooth muscle attached to lens by ciliary body-smooth muscle attached to lens by ciliary zone

regulates the amount of light entering the eye

pigmented layer that gives eye color

rounded opening in the iris

retina contains two layers

1. outer pigmented layer absorbs light and prevents it from scattering

2. inner neural layer contains receptor cells (photoreceptors)

rods

cones

absorbs light and prevents it from scattering

Contains receptor cells (photoreceptors)

rods

cones

retinal receptors that detect black, white, and gray; necessary for peripheral and twilight vision, when cones don't respond

allows for detailed color vision

dense in the center of the retina

lateral to blind spot

-Area of the retina with only cones

biconvex crystal like structure

held in place by a suspensory ligament attached to the ciliary body

cataracts result when the lens beep,es hard and opaque with age

lens divide the eye into two chamber

anterior to the lens, contains aqueous humor

posterior to the lens, contains vitreous humor

water fluid found between lens and cornea

similar to blood plasma

helps maintain interocular pressure

reabsorbed into venous blood through the scleral venous sinus (canal of schleming)

contains vitreous humor

jellylike substance found behind the lens in the posterior cavity of the eye that maintains its shape

instrument for examining the eye

can detect diabetes, arteriosclerosis, degeneration of the optic nerve and retina.

Light enters eye -> cornea -> aqueous humor -> lens -> vitreous humor -> neural layer of retina

the lens mist change sable to focus on closer objects

reversed from left to right, upside down, smaller than the object

optic charisma and optic tracts

location where the optic nerves cross

fibers from the medial side of each eye brass over to the opposite sides of the brain

contain gibers from the lateral side of the eye on the same side and the medial side of the opposite eye.

focuses imaged correctly on the retina

a condition resulting from a refractive error in which light rays entering the eye are brought into focus in front of the retina.

a refractive error in which light rays entering the eye are focused behind the retina.

Images are blurry

Results from light focusing as lines, not points, on the retina due to unequal curvatures of the cornea or lens

inhabited rod function that hinders the ability to see at night

genetic conditions that result in the ability to see certain colors

can cause blindness due to increasing pressure within the eye

causes vision loss and is an incurable eye disease, the center portion of the retina degenerates caused by genetics

the scleral venous sinus