terminology

Question 1

BC

Answer 1

base Curve refers to the radius of curvature of the central posterior surface of a contact lens. Base curse may be expressed in diopters of the surface power or in millimeters of radius of curvature. Example: 42.75 D (7.90mm)

Question 2

CAB

Answer 2

lulose acetate butyrate) - First generation, low Dk (4.0) gas permeable lens material.

Question 3

CN bevel

Answer 3

Also known as anterior bevel. Angulation placed on the anterior surface of a lens to reduce edge thickness and decrease lid sensation.

Question 4

CPC

Answer 4

Also known as the base curve (BC), the CPC is the curvature of the posterior optical portion of a contact lens

Question 5

CT

Answer 5

Center thickness of a lens is the measurement from the anterior to the posterior surface of the lens at its geometric center, in millimeters

Question 6

Dk

Answer 6

Refers to the inherent permeability of a lens material to allow the passage of gasses (oxygen) through it.

Question 7

Dk/L

Answer 7

Refers to the amount of oxygen which passes through a lens material of specified thickness.

Question 8

DW

Answer 8

contact lens designed to be worn for less than 24 hours, preferably 12 to 15 hours, with cleaning and disinfection performed between wearing periods

Question 9

EOP -

Answer 9

quivalent oxygen percentage

Question 10

EW

Answer 10

A contact lens designed to be worn for 24 hours per day, continuously, for a designated period of time.

Question 11

FSA

Answer 11

fluoro-silicone acrylate) - A rigid gas permeable material which contains fluorine for stability, wettability and added oxygen transmission, silicone for oxygen permeability, and methylmethacrylate for machinability and good optical quality.

Question 12

GMMA

Answer 12

(Glyceryl Methylmethacrylate) A non-HEMA soft lens material.

Question 13

GPC

Answer 13

Allergic type of conjunctivitis associated with soft contact lens wear.

Question 14

HEMA

Answer 14

Plastic polymer used to make soft lens material.

Question 15

HSV

Answer 15

erpes simplex virus, which can recurrently infect the cornea, producing branch-like ulcers referred to as dendritic keratitis.

Question 16

K’

Answer 16

Keratometer readings.

Question 17

OWS

Answer 17

Over-wear syndrome producing pain, sensitivity to light, corneal swelling, and epithelial erosion following prolonged wear of contact lenses.

Question 18

OZ

Answer 18

the optical zone of a contact lens is the chord diameter over which the base curve extends on the posterior surface of the contact lens. It is recorded in millimeters of diameter.

Question 19

PC -

Answer 19

he peripheral curve is the outermost curve on the posterior lens surface. Its function is to clear the flatter periphery of the cornea and to prevent lens impingement in the limbal areas as the lens moves with the blink.

Question 20

PMMA

Answer 20

(Polymethylmethacrylate) A plastic polymer used to make hard contact lenses. This type of lens is impermeable to oxygen.

Question 21

RGP

Answer 21

Rigid gas permeable contact lens

Question 22

SA

Answer 22

Silicone Acrylate, an RGP material, which combines silicone for oxygen transmissibility, and methacrylate for optical quality.

Question 23

SC

Answer 23

he secondary curve of a lens is also referred to as the intermediate curve. It lies between the base curve and the peripheral curve on the posterior surface of the lens

Question 24

SCL

Answer 24

Soft contact lens.

Question 25

SLK

Answer 25

Superior limbic keratitis.

Question 26

SPK

Answer 26

Superficial punctate keratitis

Question 27

S.O.A.P.

Answer 27

ubjective, Objective Assessment and Plan, which describes a technique for conducting an examination of a patient.

Question 28

TFBUT

Answer 28

Tear film break-up time. Measurement of the time interval between a blink and the development of a dry spot in the pre-corneal tear film. Less than 10 seconds is abnormal.