Contact Lens Vocab #1

Front 1

Astigmatism

Back 1

A condition where the cornea is irregularly shaped, causing distorted vision especially at near distances. Either glasses or toric contact lenses can correct astigmatism for most people. Up to moderate amounts of astigmatism are correctable with regular GP contacts.

Front 2

Cornea

Back 2

Clear front eye tissue that covers the iris and pupil and admits light. Contact lenses either fully or partially cover the cornea.

Front 3

Dry eye syndrome

Back 3

Dry eye usually occurs when eyes don't produce enough tears or when tears evaporate too quickly because of environmental conditions. Contact lens wearers, computer operators, post-menopausal women, and people with allergies are most susceptible to chronic dry eye.

Front 4

Emmetropia

Back 4

The scientific term for normal vision. When the cornea and lens of the eye focus an image directly on the retina, clear vision is the result.

Front 5

Enzyme cleaner

Back 5

An extra-strength cleaner, typically used weekly, to remove stubborn deposits from contact lenses. Comes in versions for both soft and GP lenses.

Front 6

1. Hyperopia

2. Myopia

Back 6

1. Farsightedness.

2. Nearsightedness

Front 7

Keratoconus

Back 7

A condition where the cornea becomes cone-shaped, causing major vision distortion. People with keratoconus are particularly challenging to contact lens fitters, who usually must prescribe custom-made lenses for them

Front 8

Iris

Back 8

The colored portion of the eye, the iris regulates the opening of the pupil.

Front 9

Acanthamoeba keratitis

(AY-can-tha-MEE-buh ker-a-TIGH-tiss):

Back 9

A rare but serious sight-destroying inflammation of the cornea caused by a parasite found in contaminated water. Most cases have been traced to the use of home-made saline solution, tap water rinses, and contaminated pools, lakes and hot tubs

Front 10

Apex of cornea (Ay-pex):

Back 10

The peak of the cornea, normally located directly over the pupil and visual axis.

Front 11

benzalkonium chloride

Back 11

A quaternary ammonium compound used as a preservative or disinfectant in eye medications and rigid lens solutions.

Front 12

blepharitis

Back 12

An inflammation of the margins of the eyelids, often caused by the staphylococcus organism.

Front 13

benzyl alcohol (BEN-zil):

Back 13

A disinfectant and preservative in rigid lens solutions.

Front 14

conjunctiva

Back 14

A thin, transparent membrane that lines the eyelids (palpebral conjunctiva) and the sclera (bulbar conjunctiva).

Front 15

conjunctivitis

Back 15

An allergic, infectious, or chemically-induced inflammation of the conjunctiva.

Front 16

corneal edema

Back 16

Swelling and fluid retention in the cornea, usually related to lack of sufficient oxygen in contact lens wearers.

Front 17

corneal ulcer:

Back 17

A sight-threatening lesion, usually bacterial in nature, and often causing permanent scarring of the cornea.

Front 18

DK value:

Back 18

A measure of the oxygen transmitted by a contact lens material

Front 19

DMV remover:

Back 19

A suction cup type of device used to remove a rigid contact lens from the eye.

Front 20

enzymatic cleaner

Back 20

A cleaner that will decompose or digest protein, muco-protein, or lipoprotein deposits on a contact lens.

Front 21

equivalent oxygen percentage (EOP)

Back 21

A lens that is impermeable to oxygen is said to have an EOP of zero; a lens completely permeable to oxygen would have an EOP of 21 (the same as the percentage of oxygen in the atmosphere). The EOP of a contact lens falls between zero and 21, depending upon its material

Front 22

fenestration

Back 22

The drilling of tiny holes in a contact lens to allow tears to circulate more freely and to provide more oxygen to the cornea through the tear exchange.

Front 23

flare

Back 23

Light streamers seen by rigid contact lens wearers whose lenses have too small an optical zone or overall diameter or whose lenses center poorly

Front 24

fluorescein

Back 24

A fluorescent dye that is instilled in the eye to evaluate the fit of rigid lenses and to highlight corneal staining, abrasions, and other corneal pathology.

Front 25

fluorescein pattern:

Back 25

The pattern formed by fluorescein-stained tears flowing under a rigid lens and observed with a Burton lamp or through the cobalt blue filter of a slit-lamp. This pattern shows the relationship between the lens and the cornea (where the lens makes contact and where there is clearance).

Front 26

gas permeable lens:

Back 26

a lens made of materials that transmit oxygen to the cornea and carry carbon dioxide and heat back to the atmosphere.

Front 27

ghost image

Back 27

A shadow-like image alongside letters or objects caused by residual astigmatism, poorly-fitting lenses, or badly-coated lenses.

Front 28

GPC (giant-cell papillary conjunctivitis)

Back 28

An inflammation of the lining of the eyelids, generally induced by the presence of denatured protein on the patient’s contact lenses rubbing against the lids. Symptoms of this auto-immune or allergic condition include itching, mucus secretion, a foreign body sensation, lens clouding, and lens slippage.

Front 29

hyperopia

Back 29

A refractive state of the eye in which parallel rays of light would come to focus behind the retina (if they were not intercepted by it). This can result from a cornea that is too flat, an eyeball with too short an axial (front-to-back) length, a crystalline lens that is too thin, or a combination of these factors. Hyperopia is commonly referred to as farsightedness.

Front 30

hypoxia

Back 30

Insufficient oxygen reaching the cornea.

Front 31

infiltrates

Back 31

Collections of white blood cells and lymphocytes in the cornea. Causes include viral infection, hypoxia, and solution sensitivity.

Front 32

K-readings

Back 32

The measurement of the flattest and steepest meridians of the patient’s cornea.

Front 33

keratitis

Back 33

An inflammation of the cornea that can be caused by mechanical irritation, solution sensitivity, allergy, infection, or other disease process

Front 34

keratoconjunctivitis

Back 34

An inflammation involving both the cornea and the conjunctiva.

Front 35

keratometer

Back 35

An instrument used to measure the curvature of the two principle meridians of the central cornea.

Front 36

keratoplasty

Back 36

Corneal transplant.

Front 37

lacrimal gland

Back 37

A gland that produces tears.

Front 38

lysozyme

Back 38

An antibacterial enzyme in tears that forms protein deposits on contact lenses.

Front 39

Mixed Solution Syndrome.

Back 39

A toxic red eye caused by mixing contact lens