Chapter 17 Eye

Question 1

pupil

Answer 1

central dark opening of the eye

Question 2

iris

Answer 2

colored portion of the eye

Question 3

conjunctiva

Answer 3

membrane lining the inner surfaces of the eyelids

Question 4

cornea

Answer 4

fibrous, transparent tissue that extends like a dome over pupil and iris

Question 5

refraction

Answer 5

bending of light rays by the cornea

Question 6

sclera

Answer 6

opaque white of the eye

Question 7

choroid

Answer 7

dark brown membrane inside sclera

Question 8

accomodation

Answer 8

normal adjustment of the eye to focus on objects from near to far

Question 9

anterior chamber

Answer 9

area behind the cornea and in front of the lens and iris

Question 10

aqueous humor

Answer 10

fluid produced by the ciliary body and found in the anterior chamber

Question 11

biconvex

Answer 11

consisting of two surfaces that are rounded, elevated, and curved evenly like a sphere.

Question 12

ciliary body

Answer 12

structure surrounding the lens that connects the iris to the choroid

Question 13

cone

Answer 13

photoreceptor cell in the retina that transforms light energy into a nerve impulse
- responsible for color and central vision

Question 14

fovea centralis

Answer 14

tiny pit or depression in the retina that the region clearest vision

Question 15

fundus of the eye

Answer 15

posterior, inner portion of the eye
- visualized with a opthalmoscope

Question 16

lens

Answer 16

small transparent, biconvex body behind the pupil of the eye
- it bends light rays to bring them into focus on the retina

Question 17

macula

Answer 17

small oval region on the retina near the optic disc
- contains fovea centralis

Question 18

optic chiasm

Answer 18

point at which optic nerves cross in the brain

Question 19

optic disc

Answer 19

region at the back of the eye where the optic nerve meets the retina
- it is the blind spot in the eye due to lack of rods and cones (only nerve fibers)

Question 20

optic nerve

Answer 20

cranial nerve carrying impulses from retina to the brain

Question 21

rod

Answer 21

photoreceptor cell of the retina for vision in low light and for peripheral vision

Question 22

thalamus

Answer 22

relay center of the brain
- optic nerve fibers pass through the thalamus on their way to the cerebral cortex

Question 23

vitreous humor

Answer 23

soft, jelly-like material behind the lens in the vitreous chamber
- helps maintain the shape of the eye

Question 24

astigmatism

Answer 24

defective curvature of the cornea or lens of the eye

Question 25

hyperopia hypermetropia

Answer 25

farsightedness

Question 26

myopia

Answer 26

nearsightedness

Question 27

presbyopia

Answer 27

impairment of vision as a result of old age

Question 28

cataract

Answer 28

clouding of the lens, causing decreased vision

Question 29

chalazion

Answer 29

small, hard cystic mass (granuloma) on the eyelid

Question 30

diabetic retinopathy

Answer 30

disease of the retina caused by diabetes melitus

Question 31

macular edema

Answer 31

fluid leaks from blood vessels into the retina and vision is blurred

Question 32

exudates

Answer 32

fluid leaking from the blood

Question 33

glaucoma

Answer 33

increased intraocular pressure results in damage to the retina and optic nerve with loss of vision

Question 34

tonometry

Answer 34

diagnoses glaucoma - instrument applied externally to eye + anesthetic

Question 35

trabeculoplasty

Answer 35

laser therapy for chronic open angle glaucoma

Question 36

blepharitis

Answer 36

inflammation of the eyelid causing redness, crusting, and swelling

Question 37

chalazion

Answer 37

granuloma formed around an inflamed sebaceous gland

Question 38

dacryocystits

Answer 38

blockage, inflammation, and infection of the nasolacrimal duct and lacrimal sac - causes swelling and redness in the region between nose and lower lid

Question 39

ectropion

Answer 39

outward sagging and eversion of the eyelid - leads to improper lacrimation, corneal drying, and ulceration

Question 40

entropion

Answer 40

inversion of the eyelid - lashes rub against the eye and corneal abrasion may result

Question 41

hordeolum (stye)

Answer 41

small, superficial white nodule along lid margin due to infection of sebaceous gland

Question 42

ptosis

Answer 42

drooping of upper lid margin from neuromuscular margin

Question 43

xanthelasma

Answer 43

raised yellowish plaque on eye lid

Question 44

nystagmus

Answer 44

repetitive rhythmic movements of one or both eyes

Question 45

retinal detachment

Answer 45

two layers of the retina separate from each other

Question 46

photopsia

Answer 46

bright flashes of lightr

Question 47

abismus

Answer 47

abnormal deviation of the eye

Question 48

esotropia

Answer 48

one eye turns inward - cross eyes

Question 49

exotropia

Answer 49

one eye turns out

Question 50

hypertropia

Answer 50

upward deviation of one eye

Question 51

hypotropia

Answer 51

downward deviation of one eye

Question 52

amblyopia

Answer 52

partial loss of vision - aka lazy eye

Question 53

diplopia

Answer 53

double vision

Question 54

fluoreacein angiography

Answer 54

intravenous injection of fluorescein dye followed by serial photographs of the retina through dilated pupils

Question 55

ophthalmoscopy

Answer 55

visual exam of the interior eye

Question 56

optical coherence tomography (OCT)

Answer 56

non-invasive imaging technique using light waves to take cross-sectional pictures of the retina

Question 57

slit lamp microscopy

Answer 57

exam of exterior ocular structures under microscopic magnification

Question 58

visual acuity test

Answer 58

clarity of vision is assessed

Question 59

visual field test

Answer 59

measurement of the entire scope of vision

Question 60

enucleation

Answer 60

removal of the entire eyeball

Question 61

keratoplasty

Answer 61

surgical repair of the cornea

Question 62

laser photocoagulation

Answer 62

intense, precisely focused light beam (argon laser) creates an inflammatory reaction that seals retinal tears and leaky retinal blood vessels

Question 63

lasik

Answer 63

use of an excimer laser to correct errors of refraction - myopia, hyperopia, astigmatism

Question 64

phacoemulsification

Answer 64

cataract removal surgery - ultrasonic vibrations breakup the lens

Question 65

scleral buckle

Answer 65

suture of a silicone band to the sclera over a detached portion of the retina

Question 66

vitrectomy

Answer 66

removal of the vitreous humor