VOCAB FOR VISION CARE Flashcards
(191 cards)
1
Q
amblyopia
A
(lazy eye) decreased vision without detectable damage in the eye or visual pathways. Possible treatment, for children only, includes occlusion of the dominant eye or eyeglasses. If bifocals are prescribed, fit mid-pupil.
2
Q
ametrophia
A
Any faulty refractive ability of the eye, such a hyperopia, myopia, or astigmatism.
3
Q
Amplitude of accommodation (AA)
A
Maximum increase in optical power of an eye produced by a change in shape of its lens
4
Q
Amsler grid
A
Graph paper like grid used in detecting central visual field distortions or defects (i.e. macular degeneration).
5
Q
andirida
A
Absence, complete or partial, of the iris.
6
Q
angle closure glaucoma
A
Sudden rise in intraocular pressure that occurs in patients with narrow anterior chamber angles. Aqueous fluid behind iris cannot pass through pupil and pushes iris forward, preventing aqueous drainage through the angle.
7
Q
aniseikonia
A
A condition in which the ocular image of an object as seen by one eye differs so much in size or shape from that seen by the other eye that the two images cannot be fused into a single impression
8
Q
anisocoria
A
unequal pupil size, when the difference is 1mm or more.
9
Q
anisometropia
A
Unequal refractive errors in the two eyes; at least 1.00 D difference
10
Q
anterior chamber
A
Area behind the cornea and in front of the lens and iris. It contains aqueous humor.
11
Q
Anterior chamber angle
A
The junction of the cornea and the iris, from which aqueous humor leaves the eye (also called filtration angle) Includes the outermost part of the angle, the front of the ciliary body, the trabecular meshwork, and the Canal of Schlemm
12
Q
anterior segment
A
Front third of the eyeball
13
Q
anterior synechiae
A
Fibrous adhesions of the iris to the cornea or trabecular
14
Q
Antimetropia
A
One eye is hyperopic and the other is myopic.
15
Q
aphakia
A
An eye that has had the crystalline lens removed.
16
Q
aqueous humor
A
The clear, watery fluid contained in the space between the cornea and iris of the eye. Flows between and nourishes the lens and cornea. The fluid is secreted by the ciliary processes.
17
Q
arcus senilis
A
An opaque ring, gray to white in color, that surrounds the periphery of the cornea. there are no symptoms, does not disturb vision, and requires no treatment.
18
Q
asthenopia
A
Eyestrain. When the eyes get tired from excessive or intense use. Symptoms may include pain in the eyes, headache, dimness of vision, etc…
19
Q
astigmatism
A
Optical defect in which the refractive power is not the same in all meridians and must be corrected with cylinder or toric lenses. “With the rule” is the most common, this is when the minus axis meridian is at or near (within 30 degrees) the 0 to 180 meridian.
20
Q
axial myopia
A
eyeball is too long
21
Q
basement membrane
A
A thin sheet of extracellular substance to which the basal surfaces of membranous epithelial cells are attached; also called the basal lamina.
22
Q
bilateral
A
Affecting or occurring on both sides.
23
Q
binocular vision
A
The blending of the separate images seen by each eye into a single image going to the brain, allowing three dimensional images, which leads to depth perception.
24
Q
bleb
A
a small blister like sac filled with a watery fluid
25
blepharitis
Inflammation of the lid margins
26
blindness
Usually defined as central visual acuity of 20/200 or less in the better eye after correction, or visual acuity better than 20/200 if there is a field defect in which the widest diameter of the visual field subtends an angle distance no greater than 20 degrees (some states include up to 30 degrees
27
blind spot
(1) A small area of the retina where the optic nerve enter the eye; occurs normally in all eyes. (2) Any gap in the visual field corresponding to an area of the retina where no visual cells are present; associated with eye disease.
28
Bowman's membrane
One of the five layers that is located just under the epithelium and above the corneal stroma.
29
Canal of Schlemm
A circular canal situated at the juncture of the sclera and cornea through which the aqueous humor is excreted after it has circulated between the lens ands the iris and between the iris and the cornea.
30
canthus
The angle formed by the meeting of the upper and lower eyelids at either side of the eye.
31
cataract
Any opacity of the crystalline lens. As the cataract develops near acuity may improve due to the myopic shift. This is called "second sight." The only treatment is surgery. Once the lens is removed it is known as aphakia. If the lens is replaced with an intraocular lens (IOL) it is called pseudophakia. Spectacle lens magnifies the aphakic image about 25%, contact lens magnifies about 7%.
32
chalazion
Small tumor of eyelid due to inflammatory enlargement of a Meibomian gland. (Stye)
33
chiasm
The point where the optic nerves from each eye are combined.
34
choroid
Layer behind retina that contains blood vessels and nourishes the retina.
35
cilia
eyelashes
36
ciliary body
Tissue inside the eye made up of ciliary muscles and ciliary processes.
37
ciliary processes
The projections of the ciliary body that secrete aqueous humor.
38
cilium
eyelashes
39
color blindness
Is the inability or decreased ability to see color, or perceive color differences, under normal lighting conditions.
40
cones
Retinal cones are concerned with visual acuity and color discrimination.
41
conjunctiva
The thin membrane covering the anterior surface of the eyeball and lining the eyelids.
42
conjunctivitis
Inflammation of the conjunctiva. Also called "pink eye"
43
Conoid of sturm
a representation of how rays are refracted through two different powered meridians (eg: a sphero- cylindrical lens). So, instead of one focal point, they form two focal lines.
44
convergence
(1) An inward turning of the eyes as when looking at a near object. (2) The action of light rays traveling toward a real image point.
45
Cornea
Transparent front semant of the eye. Provides most of the eye reflective power (approx. 43 D). It is composed of 5 identifiable layers. From anterior to posterior: Epithelium, Bowman's membrane, Stroma, Descemet's membrane, and the Endothelium. The epithelium heals without scarring in 24-48 hours. bowman's membrane scars if damaged. The stroma comprises 90% of the corneal bulk. The endothelium has little is any regenerative ability.
46
corneal abrasion
A scraped area of corneal surface with loss of superficial tissue (epithelium)
47
corneal ulcer
infection on the surface of the eye caused by injury dryness due to lack of tear production, or infection.
48
Curvature myopia
the eye is normal size but the curvatures of the lens and cornea are increased (steeper)
49
cycloplegics
A transparent biconvex lens structure located between the iris and vitreous. It is attached to the ciliary processes and to the posterior portion of the ciliary body by means of fine suspensory ligaments referred to as the zonular fibers. It protects the retina from UVA by absorbing ultraviolet light between 310 and 410 nm. Index of refraction 1.398.
50
dacryocystitis
Inflammation of the lacrimal sac
51
Decemet's membrane
Thin, elastic layer deep in the cornea formed by the endothelium and composed of collagen and elastic fibrils.
52
depth perception
Ability to perceive the solidity of objects and their relative position in space; also called stereoscopic vision.
53
deviation
Misalignment of eyes caused by muscle imbalance.
54
diabetic retinopathy
A spectrum of retinal changes accompanying long-standing diabetes mellitus.
55
dialator papillae
The iris muscle
56
diopter
A measurement of the degree to which light converges or diverges; also of lens refractive power. Equal to the reciprocal of the focal length of a lens (in meters), e.g., a 2-diopter lens brings parallel rays of light to a focus at half a meter.
57
diplopia
Seeing one object as two
58
divergence
The outward rotation of the two eyes to see in the distance
59
ectropion
where the lower eyelid droops away from the eye and turns outwards
60
edema
Excessive accumulation of fluid in the tissue spaces, due to disturbance in the mechanism of fluid exchange.
61
emmetropia
When distance objects are focused on the retina by an eye with relaxed accommodation
62
endothelium
A monolayer of specialized, flattened cells that line the posteri or surface of the cornea
63
entropion
An inward turning of the margin of an eyelid.
64
enucleation
Complete surgical removal of the eyeball (or tumor, or other body) without rupture
65
epithelium
The epithelial tissue that covers the front of the cornea
66
esophoria
A tendency of one eye to deviate towards the nose. Can be overcome by fusion
67
esotropia
(Crossed eyes) A manifest deviation of one eye towards the nose. Cannot be overcome by fusion.
68
evisceration
An operation that removes the contents of the eyeball
69
exophoria
A tendency of one eye to deviate outward from the nose
70
exotropia
(Wall eyed) A manifest deviation of one eye outward from the nose.
71
extrinsic muscles
The six muscles of the eyeball; medial and lateral recti, superior and inferior recti, and superior and inferior oblique.
72
eye
The organ of vision as a whole. It is made up of three tunics or coats, (1) The fibrous tunic (sclera and cornea). (2) The vascular tunic (choroid, ciliary body, and the iris). (3) The nervous tunic (optic nerve and its outspreading into the retina).
73
eyelids
Structures covering the front of the eye that serve to protect it and limit the amount of light entering the pupil. Also distribute the tear film over the exposed corneal surface.
74
far point
The location of the farthest object on which the fully relaxed eye can focus. For a normal eye, the far point is located at infinity.
75
farsighted
hyperopia
76
field of vision
That area that can be seen without shifting the eye.
77
fissure, palpebral
The opening between the eyelid margins.
78
floaters
Are deposits of various size, shape, consistency, refractive index, and motility within the eye's vitreous humor, which is normally transparent.
79
fornix
The are where the conjunctiva covering the eyeball meets the conjunctiva lining the eyelid.
80
fovea centralis
Depression in the macula adapted for most acute vision
81
fundus
The interior lining of the eyeball, including the retina, optic disc, and macula; portion of the inner eye that can be seen during an eye examination by looking through the pupil.
82
fusion
The coordination of the two separate images from the two eyes of the same object into one image. Occurs in the brain.
83
glaucoma
This is a group of diseases characterized by increased intraocular pressure, field loss, and damage to the optic nerve and retinal nerve fibers. Mean IOP 15Hg, "normal" 9-21Hg refer for exam.
84
Grave's Ophtalmopathy
Eye signs that may occur with excessive thyroid-related hormone concentration. Includes eyelid retraction, bulging eyes, corneal drying and optic nerve inflammation.
85
hematoma
Swelling of the tissues due to a hemorrhage.
86
heterophoria
failure of the visual axes to remain parallel after elimination of fusion.
87
hordeolum
see stye
88
hyperopia
A condition in which visual images come to a focus behind the retina of the eye and vision is better for distant than for near objects -- called also farsightedness.
89
hyperphoria
Tendency for the eye to deviate upwards when the other eye is covered. May be corrected with base up and base down prism.
90
hyphema
blood in the anterior chamber of the eye
91
intraocular
within the eye
92
intraocular pressure
pressure of the fluid inside the eye; normal IOP varies among individuals
93
iridectomy
A glaucoma treatment in which a section of the iris is removed to create a small opening in the periphery
94
iris
The circular pigmented membrane behind the cornea, perforated by the pupil; the most anterior portion of the vascular tunic of the eye.
95
iritis
Inflammation of the iris. Can cause pain, tearing, blurred vision, small pupil and a red congested eye.
96
isotropic
The same refractive error in both eyes
97
Jaeger Chart
A chart used to test near vision
98
keratitis
inflammation of the cornea
99
Keratitis sicca
Dryness of the cornea
100
Keratoconus
Steepening and thinning of the central cornea. Identified as a cone shaped deformity.
101
keratoplasty
Replacement of scarred or damaged cornea with new donor cornea
102
lacrimal
relating to tears
103
lacrimal duct
The duct that carries tears from the lacrimal sac into the nasal cavity
104
lacrimal gland
The small almond shaped structure that produces tears; located just above the outer corner of the eye
105
legal blindness
In the U.S. visual acuity of 20/200 or worse in the better eye with corrective lenses; visual field restricted to 20 degrees diameter or less (tunnel vision) in the better eye
106
lens
see crystalline lens
107
levator palpebrae superioris
Levator muscle; muscle that raises the upper eyelid
108
limbus
The border of the cornea and the sclera
109
line of sight
an imaginary line connecting viewed object and the fovea
110
low vision
Visual loss that cannot be corrected with eyeglasses or contact lenses and interferes with daily living activities
111
macula
The small avascular area of the retina surrounding the fovea and that with the fovea comprises the area of the retina that gives distinct vision
112
macular degeneration
Partial or complete loss of central vision due to degeneration of the macular region of the retina
113
meibomian gland
located within the lids. Secretes oily layer of tear fluid.
114
microphthalmos
an abnormally small eyeball
115
miotic
relating to the contraction of the pupil
116
monocular
pertaining to one eye
117
muscles
Movement of the eye is controlled by 6 extraocular muscles located on the outside of the eyeball. There are 3 intraocular muscles located inside the eyeball; ciliary, sphincter pupillae, dilatoe pupillae
118
mydriatic
drug used to dilate the pupil
119
myopia
nearsightedness; the condition in which parallel rays of light are brought into focus in front of the retina, rather than on it
120
near point of accommodation
The nearest point at which the eye can perceive print distinctly
121
Near Point of Convergence
The nearest single point at which the 2 eyes can maintain single binocular vision
122
nearsighted
myopia
123
near triad
When fixating on near objects the eye accommodates, the pupil constricts and the eyes converge
124
neovascularization
Recent formation of new blood vessels in a part e.g. in cornea
125
nystagmus
A spasmodic rotary or side to side movement of the eyes often associated with albinism
126
O.D.
oculus dexter (right eye)
127
Ophthalmia
Severe, often purulent conjunctivitis. Inflammation of the deeper structures of the eye.
128
Optic atrophy
Degeneration of the tissue of the optic nerve
129
optic chiasm
Crossing of the fibers of the optic nerves on the lower surface of the brain
130
optic cup
the white, cup-like area in the center of the optic disc
131
optic disk
Visible portion of the optic nerve
132
O.S.
ocular sinister (left eye)
133
O.U.
both eyes
134
palpebra
eyelid
135
palpebral fissure
the space between the upper and lower lid
136
P.D.
an abbreviation for pupillary distance
137
peripheral vision
Side vision. The ability to see objects and movement outside of the direct line of vision.
138
phakic
an eye with the crystalline lens intact
139
phoria
A tendency for the eye to deviate
140
photophobia
An abnormal sensitivity to or intolerance of light by the eyes as may be caused by eye inflammation, lack of pigmentation in the iris or various diseases
141
photopic vision
Daylight vision which depends primarily on the function of the cones
142
pingueculum
A benign, yellowish-brown subconjunctival elevation that is usually located on either side of the cornea
143
posterior
Situated behind or at the read
144
posterior chamber
The space between the back of the iris and the front face of the vitreous; filled with aqueous fluid
145
posterior synechia
Adhesion of the iris to the crystalline lens
146
Presbyopia
(old age vision) This is a refractive condition that occurs when the loss of accommodation no longer allows for reading at the accustomed length. This usually begins around 40-45 years of age and is corrected with plus powers for reading.
147
Pseudophakia
An eye that had the crystalline lens replaces with an intraocular implant (IOP)
148
Pterygium
A disease of the eye. A triangular fold of tissue which extends from the conjunctiva onto the cornea.
149
Ptosis
A disease of the eye. A triangular fold of tissue which extends from the conjunctiva onto the cornea.
150
Pupil
The variable-sized, black circular opening in the center of the iris that controls the amount of light that enters the eye. The average size of the pupil in normal lighting is 3-5mm.
151
Pupillary reflex
Contraction of the pupil when exposed to light and dilation when the light is removed.
152
radial keratotomy
The flattening of the central cornea by 8 to 16 radical cuts shaped like the spokes on a wheel.
153
Recession
The affected muscle is detached and reattached farther back back on the eye to weaken the relative strength of the muscle.
154
Refraction
A test to determine the best eyeglasses or contact lenses to correct a refractive error (myopia, hyperopia, or astigmatism).
155
Refractive Error
A defect in the eye that prevents light rays from being brought to a single focus exactly on the retina.
156
Refractive media
The transparent parts of the eye having refractive power.
157
refractive myopia
caused by increased index of refraction of the lens, as in cataracts
158
resection
A surgical procedure where a section of the ocular muscle is removed and reattached to strengthen the muscle.
159
Retina
The light sensitive layer of tissue that lines the back of the eyeball; sends visual messages through the optic nerve to the brain.
160
Retinal detachment
A separation of the retina from the choroid.
161
Retinal pigment epithelium
The pigment cell layer that nourishes the retinal cells; located just outside the retina and attached to the choroid.
162
Retinitis
Inflammation of the retina
163
Retinitis Pigmentosa
hereditary progressive retinal degeneration in both eyes. Night blindness develops, usually in childhood, followed by the progressive loss of peripheral vision progressing over many years to tunnel vision and finally blindness.
164
Retinoscope
An instrument used the measure the refractive power of the eye.
165
Retrobulbar
Situated or occurring behind the eyeball.
166
Rods
One type of specialized light-sensitive cells (photoreceptors) in the retina that provide side vision and the ability to see objects in dim light (night vision).
167
Schlemm's Canal
the passageway for the aqueous fluid to leave the eye
168
Sclera
The tough white supporting tunic of the eyeball; the supporting tunic of the eyeball, covering approximately the posterior five-sixths of its surface
169
Scotoma
blind spot in vision
170
Scotopic
The ability to see darkness or dim light; dark-adapted vision and depends primarily on the function of the rods
171
Sjogren's syndrome
An inflammatory disease that can affect many different parts of the body, but most often affects the tear and saliva glands
172
Snellen E
This is a test chart used to assess visual acuity. The letters are constructed so that a specified distance it subtends an angle of 5 minutes of arc. Each portion of the letter subtends and angle of 1 minute of arc. This test is usually performed at 20 feet.
173
Sphincter pupillae
The muscle that contracts the iris, narrowing the diameter of the pupil of the eye.
174
Stereoscopic vision
Vision in which objects appear the be 3D as compared to flat
175
Strabismus
A manifest deviation of an eye.
176
Stye
inflammation of the sebaceous glands of the eyelid
177
suppression
Suppressing one image that is out of focus or doubled
178
suspensory ligament
Fibers that connect the ciliary body to one's lens
179
st
Any adhesion, specifically adhesion of the iris to cornea or lens
180
Tarsus
The framework of connective tissue which gives solidity and shape to the edges of the eyelids.
181
tear duct
Opening in the medial lower eyelid that allows tears to drain into the nose
182
Tenon's capsule
This membrane which envelops the eyeball from the optic nerve to the limbus
183
Tonometer
An instrument used to measure intraocular pressure.
184
Tonometry
The standard to determine the fluid pressure inside the eye (intraocular pressure)
185
Trabecular meshwork
The spongy, mesh-like tissue near the front of the eye that allows the aqueous fluid (humor) to flow to Schlemm's canal then out of the eye through ocular veins
186
trachoma
A contagious viral conjunctivitis, which in the chronic form produces severe scarring of the eyelids and cornea. The leading cause of blindness in the world
187
tropia
a manifest deviation of an eye from the normal position when both eyes are open and uncovered
188
uvea/uveal tract
The middle coat of the eyeball, consisting of the choroid in the back of the eye and the ciliary body and iris in the front of the eye
189
Visual acuity
The ability to distinguish details and shapes of objects; also called central vision
190
Visual field
The entire area that can be seen when the eye is forward, including peripheral vision.
191
vitreous
The transparent, colorless mass of gel that lies behind lens and in front of retina
