suspensory ligaments
secures the lens to the ciliary body
fluid that fills the anterior segment of the eye, provides nutrients to the lens and the cornea
fibrous tunic, white and opaque
area of retina that lacks photoreceptors
ciliary body
muscular structure that manipulates the lens
choroid coat
nutritive (vascular) tunic of the eye
canal of schlemm
drains the aqueous humor the eye
tunic concerned with image formation
vitreous humor
gel-like substance, filling the posterior segment of the eyeball, helps reinforce the eyeball
far point of vision
the point beyond which accommodation is unnecessary
concave lens
lens that is thickest at the edges, diverges the light rays
focal point
the point at which light rays are converged by a convex lens
visible light
the electromagnetic waves to which the photoreceptors of the eyes respond
near point of vision
the closest point at which clear focus is possible
variety of cones
night blindness
result of vitamin a deficiency
accommodation pupillary reflex
reflex constriction of the pupils when viewing close objects
medial movement of the eyes during focusing on close objects
normal vision
light bending
condition of increasing pressure inside the eye, resulting from blocked drainage of aqueous humor
blurred vision, resulting from unequal curvations of the lens or cornea
ability to focus for close vision, What is the ability of the eye to focus specifically on close objects (those less than 20-feet away)?
freshy elevation at the medial canthus
angular point where the eyelids meet
mucous secreting membrane of the eyelid that folds back to cover the eyeball except for the cornea
ciliary glands
glands between the eyelashes
meibomian glands
modified sebaceous glands embedded in the tarsal plates, lubricate the eye
number of external eye mucles
inflammation of the conjunctiva, eyes are red and inflammed
infectious form of conjuctivitis
white of the eye
clear portion of the sclera (front of eye), no blood vessels
under the sclera, rich blood supply, had dark pigment to prevent light from scattering
ciliary body
lens attached to it, smooth muscle
pigments, opening to the pupil
circular muscles
these muscles contract the pupil constricts in bright light
raidal muscles
these muscles contrac the pupil dilates in dim light
innermost sensory tunic, contains millions of photoreceptors
more dense at the periphery, for night vision, no color distingtion
bright light, 3 types, dense at the center of the retina
macula lutea
yellowish spot at the central region of the retina, contains the fovea centralis
fovea centralis
lateral to each blind spot, contains only cones, sharpest point of vision
blue, gree, green/red
cone types
color blindness
problens with the cones
suspended by ciliary body, hardened jelly
aqueous humor
provides nutrients to lens and cornea and maintains intracular pressure, reabsorbed into venous blood through the canal of schlemm
vitreous humor
gel-like, prevents the eye from collapsing
optic chaisma
fibers from the medial side of each eye cross over to the opposite side (remember brain diagram)
optic tracts
neuron fibers tracts from the optic nerve that go to the thalamus and then to the occipital lobe of the brain
photopupillary reflex
bright light causes pupils to constrict (reflex)
image if focused behind the retina, eyeball is too short, farsightedness
damage to the visual cortex causes loss of vision to the same side of both eyes...cause=CVA(cerebral vascular accident/stroke)
medial and lateral canthus
where eyelid meets on each side
lacrimal glands
release a dilute salt soltion on eye from small ducts
lacrimal canals
tears flush across eyeball to here
lacrimal sac/nasolacrimal duct
where tears end up
lateral rectus
moves eye laterally
medial rectus
moves eye medially
superiour rectus
elevates eye
inferior rectus
depresses eye
inferior oblique
elevates eye and turns laterally
superior oblique
depressed eye and turns it laterally
bipolar cells
middle ground between rod/cones and ganglion cells
ganglion cells
bring impules to the optic nerve
coats filled w fluids to maintain shape
A delicate membrane that lines the eyelids and covers the part of the outer surface of the eyeball is called the
shape of the lens
Focusing the light rays involves which of the following?
3, 1, 5, 6, 2, 4, 7
Choose the correct path of light entering the human eye.
1. cornea
2. lens
3. conjunctiva
4. vitreous humor
5. aqueous humor
6. pupil
7. retina
conjunctiva; cornea
A delicate membrane, the _______ lines the eyelids and covers part of the outer surface of the eyeball. It ends at the edge of the _______ by fusing with its epithelium.
to make an oily secretion to lubricate the eye
What is the function of the meibomian glands?
The only special sense which is NOT functional when the child is born is:
cornea and sclera
What makes up the outermost tunic of the eye?