Random CL questions 2

Question 1

a combination solution for rigid contact lenses that contains both wetting agents and disinfecting chemicals

Answer 1

Wetting & Soaking solution

Question 2

Silicone and oxygen are made into a siloxane which is then copolymerized with PMMA to create an oxygen permeable material used in the manufacture of rigid lenses

Answer 2

Siloxane/Silicon Acrylates

Question 3

Vision that is temporarily distorted or out of focus when a contact lens wearer, particularly a rigid contact lens wearer, switches from contact lens to glasses.

The blur may be caused by corneal edema, mechanical molding, or a combination of two

Answer 3

Spectacle Blurr

Question 4

a mercury compound, used as a preservative in some contact lens solutions, that has been implicated as the cause of many red eyes and other adverse reactions in contact lens wearers

Answer 4

Thimerosal

Question 5

retention of fluorescein dye by damaged corneal tissue

Answer 5

Corneal staining

Question 6

a substance that enables tears to spread evenly over the surface of a rigid contact lens and helps to cushion the lens on insertion

Answer 6

Wetting agent

Question 7

a detergent-like cleaner that emulsifies debris and removes foreign substances from the surfaces of a contact lens

Answer 7

Surfactant Cleaner

Question 8

the pumping in of fresh, oxygenated tears between the contact lens and the cornea and the pumping out of deoxygenated tears and metabolic wastes with each blind

This is necessary to maintain normal corneal metabolism

Answer 8

Tear Exchange

Question 9

the process of reducing the number of viable micro-organisms to a level which is harmful neither to ocular health nor the quality of contact lenses and accessories

Answer 9

Disinfection

Question 10

the date, designated by the manufacturer, beyond which a product should not be first used

Answer 10

Expiry Date

Question 11

Inflammatory cells within the cornea occurring as a response to viral or other infection, toxic or chemical stimulus

Typically seen as greyish disciform patches near the limbus

Answer 11

INFILTRATES

Question 12

a storage solution used to enhance the biocompatibility of RGP lens surfaces

Answer 12

Conditioning Solutions

Question 13

agent intended to prevent the growth of micro-organisms in a care product

Answer 13

Preservatives

Question 14

soft contact lens used to protect the cornea, reduce pain and assist healing in conditions such as bullous keratopathy, ulcers and burns

Answer 14

Therapeutic CL (for aniridia) / Bandage CL

Question 15

Hydrogel lens prior to hydration:

Answer 15

Xerogel

Question 16

Lens design consisting of the central radius and two peripheral curves

Answer 16

Tricurve

Question 17

Fitting technique where the BOZR is selected to be parallel to the corneal surface

Answer 17

Parallel fit / Alignment Fit

Question 18

Lens design consisting of the central radius and multiple peripheral curves

Answer 18

Multicurve

Question 19

angle formed by a tangent to a sessile drop of fluid at the point where the drop meets a surface.

a more wettable material has a smaller angle of contact

the angle is zero for a completely hydrophilic material

Answer 19

Contact Angle

Question 20

irregularity in the size of cells of the corneal endothelium

observed in extended wear and in long-standing PMMA wearers

Answer 20

Polymegathism

Question 21

Method of soft lens manufacture employing heat and closed moulds

Answer 21

Cast molding

Question 22

a contact lens fitting, usually steep, in which there is a proof of tears between the back surface of a hard lens and the anterior surface of the corneal apex

generally observed with fluorescein

Answer 22

Apical Clearance / Pooling

Question 23

the time in seconds for the break up of the precorneal tears film in a non-blinking eye

generally observed with fluorescein and the slit lamp

Answer 23

TBUT

Question 24

small vesicles in the corneal epithelium containing fluid and cellular debris

occurs as a typical response to corneal stress, particularly extended wear

Answer 24

Microcyst

Question 25

staining of the nasal and temporal areas of the peripheral cornea Frequently associated with conjunctival injection in the horizontal meridian Influenced by dry eyes, poor blinking, lens design and lens material

Answer 25

3 & 9 o'clock Staining

Question 26

distance between a point on the back surface of a lens at a specified diameter and the continuation of the back central optic zone Measured along a radius of curvature of the latter

Answer 26

Radial edge shape

Question 27

a contact lens fitting, usually flat, in which the back surface of the lens rests on the apex of the cornea Generally observed with fluorescein

Answer 27

Apical Touch

Question 28

a solution having the same tonicity as 0.9% sodium chloride

Answer 28

Isotonic Solution

Question 29

the shaping of a lens, normally with a straight edge to assist with correct orientation on the eye in Toric or bifocal fitting

Answer 29

Truncation

Question 30

the formation of trapped air bubbles beneath a contact lens usually associated with hard lenses but can also occur with soft lenses

Answer 30

Dimpling

Question 31

the thickness of the layer of tears between the back surface of a contact lens and the front surface of the cornea

Answer 31

Tear Layer

Question 32

Technique for correcting presbyopia in which reading addition is incorporated into the contact lens for the non-dominant eye

Answer 32

MonoVision

Question 33

achieved with a bifocal contact lens which positions both distance and reading portions in front of the pupil at the same time

Answer 33

Simultaneous Vision / Multifocal

Question 34

Lens design where part of all of the back surface is of toric construction the front surface may be either spherical or toroidal in which case it is a bitoric

Answer 34

Back Surface Toric

Question 35

The reduction, modification or elimination of a visual defect by a programmed application of contact lenses The technique for reducing myopia consists of changing the shape of the cornea by fitting a series of hard lenses progressively flatter than “K” Also called corneal refractive therapy (CRT) and Overnight vision correction (OVC)

Answer 35

Ortho-K / OrthoKeratology

Question 36

achieved with a bifocal contact lens which has distinct zones for distance and near The lens must translate for the different portions to line up with the pupil area for the appropriate visual task The reading segment may be either fused or solid and only hard lenses have only proved successful

Answer 36

Alternating Vision

Question 37

Soft lens materials made from a combination of silicone rubber and hydrogel monomers

Answer 37

Silicon Hydrogel

Question 38

Translucent or opalescent dimples containing cellular debris trapped behind a contact lens Most often associated with silicone hydrogels and sometimes known as lipid plugs or pre-corneal deposits

Answer 38

Mucin Balls

Question 39

Lens design consisting of the central radius and one peripheral curve

Answer 39

Bi-Curve

Question 40

Methods used to measure the stability of the tears film without a staining agent employing a cold diffuse light source or grid pattern for observation

Answer 40

NITBUT

Question 41

Loss of tolerance to contact lenses from long-term hypoxia resulting in chronic oedema

Answer 41

Corneal Exhaustion Syndrome / Intolerance

Question 42

Method of soft lens manufacture employing liquid polymer spun to the required shape in rotating open moulds

Answer 42

Spin Casting

Question 43

Extreme, painful response to gross corneal edema as a result of excessive contact lens wear usually found with PMMA and typically occurring in the middle of the night

Answer 43

Over Wear Syndrome

Question 44

The smoothing of a lens transition with a curve intermediate between the two radii Blending may be light, medium or heavy

Answer 44

Blending

Question 45

A lens where the second radius is steeper than the base curve Such lenses are used mainly for orthokeratology but also for other fitting applications such as corneal grafts and post refractive surgery

Answer 45

Reverse Geometry

Question 46

a contact lens which fits over both the cornea and bulbar conjunctiva Typical overall sizes are 22-24mm

Answer 46

Scleral Lens

Question 47

a small disc made of various silicone and or various silicone and or plastic materials usually containing an optical correction which is worn over the cornea as an alternative to spectacles which can correct ametropias and presbyopia

Answer 47

Contact Lens

Question 48

Contact Lens manufacturing method in which dry buttons of the lens material are cut with lathes most labor intensive and least reproducible method of contact lens manufacture, but useful for production of small quantities or custom parameters

Answer 48

Lathe Cutting

Question 49

a discontinuity or break in the epithelial tissue of thecornea associated with inflammation in the cornea that could be sterile or may be caused by bacterial, fungal or viral infection

Answer 49

Corneal Ulcer

Question 50

a discontinuity or break in the epithelial tissue of the cornea associated with inflammation in the cornea that could be sterile or may be caused by bacterial, fungal or viral infection

Answer 50

Corneal Ulcer

Question 51

The amount of oxygen diffusing through a given amount of lens material in a give amount of time, under specified testing conditions

Answer 51

Oxygen Permeability