structures of the eye

Question 1

lacrimal apparatus

Answer 1

protects, moistens, and lubricates the eye

Question 2

lacrimal gland

Answer 2

produces lacrimal fluid (tears)

Question 3

lacrimal canals

Answer 3

drains lacrimal fluid from the eyes

Question 4

lacrimal sac

Answer 4

provides passage of lacrimal fluids to nasal cavity

Question 5

nasolacrimal duct

Answer 5

empties lacrimal fluid into the nasal cavity

Question 6

sclera

Answer 6

thick white connective tissue, “white of the eyes”

Question 7

cornea

Answer 7

transparent, central anterior portion, allows for light to enter the eye

Question 8

choroid

Answer 8

a dark pigment in the middle of the eye that prevents light from scattering w/i the eye

Question 9

ciliary body

Answer 9

a smooth muscle structure w/i the choroid to which the lens and iris are attached

Question 10

suspensory ligament

Answer 10

fibers that connect the ciliary body with the lens

Question 11

lens

Answer 11

transparent biconvex structure, divides the eye into anterior and posterior chamber, focuses light rays onto the retina

Question 12

iris

Answer 12

pigmented layer that gives eye color

Question 13

pupil

Answer 13

rounded opening in the iris that controls the amount of light directed to the retina, dilates and constricts to control light

Question 14

retina

Answer 14

innermost sensory tunic of the eye (light-sensitive nerve tissue) containing photoreceptors; converts light into electrical impulses

Question 15

photoreceptors (rods & cones)

Answer 15

rods: edge of retina, allow dim light and peripheral vision
cones: center of retina, allow for detailed colored vision

Question 16

optic nerve

Answer 16

composed of ganglion cell axons, transmits electrical impulses from the eyes to the brain

Question 17

optic disk (blind spot)

Answer 17

no photoreceptors at the OD, results in break in the visual field

Question 18

macula

Answer 18

translates light that enters the eye into the images we see; responsible for center vision that lets you see what’s right in front of you

Question 19

fovea centralis

Answer 19

a small pit in the macula provides sharp central vision (reading, driving, sowing)

Question 20

cataracts

Answer 20

the hardening of the lens resulting in hazy vision and eventually blindness

Question 21

glaucoma

Answer 21

optic condition caused by a blocked aqueous humor, compression of the retina and optic nerve; causes pain and possible blindness

Question 22

aqueous humor

Answer 22

watery fluid found in the anterior chamber, helps maintain intraocular pressure, provides nutrients for the lens and cornea

Question 23

vitreous humor

Answer 23

clear gel-like substance in the posterior chamber, provides reinforcements that keep the eye from collapsing; refractory structure

Question 24

scleral venous sinus (canal of schlemm)

Answer 24

at the junction of the sclera and cornea, collects aqueous humor and delivers it to the bloodstream

Question 25

accommodation

Answer 25

the ability of the eye to focus on objects less than 20ft away

Question 26

optic chiasma

Answer 26

conveys visual info from the eye to the occipital lobe

Question 27

optic tracts

Answer 27

bundle of nerve fibers carrying visual info from the optic chiasma to the brain

Question 28

optic radiation

Answer 28

axons in the thalamus, transmits visual input from the retina, optic nerve, and optic tract

Question 29

convergence

Answer 29

the reflexive movement of the eyes medially when viewing close objects

Question 30

photopupillary reflex

Answer 30

eyes constricting when exposed to bright light

Question 31

accommodation pupillary reflex

Answer 31

pupils constricting when viewing close objects to provide more acute vision

Question 32

emmetropia

Answer 32

normal eye vision

Question 33

hypermetropia or hyperopia

Answer 33

being farsighted; light rays are focused behind retina

Question 34

myopia

Answer 34

being nearsighted; light focused in front of retina

Question 35

presbyopia

Answer 35

near and far is blurry; caused by weak ciliary muscles or decreased convexity of lens

Question 36

astigmatism

Answer 36

unusual curvature of cornea