Definitions PT1/2

Question 1

Emmetropia

Answer 1

a normal eye with no refractive error

Question 2

Ametropia

Answer 2

an eye abnormality (hyperopia, myopia and astigmatism) resulting from a faulty refractive ability of the eye

Question 3

Presbyopia

Answer 3

farsightedness caused by loss of elasticity of the lens of the eye, occurring typically in middle and old age

Question 4

Hyperopia

Answer 4

AKA farsightedness.
Distant light rays of light focus behind the retina when the eye is at rest.
Plus lens is used for correction.
Causes: short axial length, flatter than normal corneal curvature, smaller eye

Question 5

Latent

Answer 5

hyperopic error that can be corrected by the eye’s accommodation

Question 6

Manifest

Answer 6

hyperopic error that can be corrected by either plus lenses or by the patient’s own accommodation

Question 7

Absolute hyperopia

Answer 7

hyperopic error that is not compensated for by accommodation (needs corrective lenses)

Question 8

Myopia

Answer 8

AKA nearsightedness.
Parallel light rays of light focus in front of the retina when the eye is at rest.
Minus lens is used for correction.
Causes: steeper than normal cornea, a longer than normal eye

Question 9

Axial myopia

Answer 9

eyeball is too long for the normal refractive power of the lens and cornea

Question 10

Curvature myopia

Answer 10

eye is of normal size but the curvatures of the cornea and lens are steeper

Question 11

Index myopia

Answer 11

change in the index of refraction of the lens (cataracts or diabetes can cause); requires minus lens to compensate

Question 12

Astigmatism

Answer 12

condition where light rays are not refracted equally in all directions, so a focus point on the retina is not attained

Question 13

Regular astigmatism

Answer 13

correctable by spherocylinder lenses and the principal meridians are at right angles to each other

Question 14

Simple (astigmatism)

Answer 14

one of the focal lines always falls on the retina, the other falls in front (myopic) or behind (hyperopic) it

Question 15

Compound (astigmatism)

Answer 15

both focal points lie either in front (myopic) of the retina or behind (hyperopic) it

Question 16

Mixed astigmatism

Answer 16

one focal point lies behind the retina, whereas the other focal point lines in front of it

Question 17

Irregular astigmatism

Answer 17

the surface of the cornea is not smooth (irregular) and therefore light rays do not refract in a predictable way to a single point.
Causes: trauma, inflammation and/or scar tissue

Question 18

Outer coat

Answer 18

cornea, sclera and limbus

Question 19

Middle coat

Answer 19

uvea, which consists of iris, ciliary body (ciliary muscles and ciliary processes) and choroid

Question 20

Inner coat

Answer 20

retina, optic nerve and optic disc

Question 21

Outer lipid layer

Answer 21

prevents evaporation of aqueous layer

Question 22

Aqueous layer

Answer 22

provides nutrition and defense

Question 23

Inner mucoid layer

Answer 23

keeps tear film on the epithelium

Question 24

Focal power formula

Answer 24

P=1/f

Question 25

Pupillary distance

Answer 25

distance between the centers of each pupil in each eye. Determines where to put the optical center in each lens

Question 26

COBC Code of Ethics

Answer 26

``` General Duty to the public Duty to clients Duty to the profession Duty to colleagues ```

Question 27

General

Answer 27

honest and knowledgeable, improve clients well being

Question 28

Duty to the public

Answer 28

educating the public in promotion of ophthalmic health

Question 29

Duty to clients

Answer 29

confidentiality, maintain records

Question 30

Duty to the profession

Answer 30

don't warrantee or guarantee success of care or treatment

Question 31

Duty to colleagues

Answer 31

don't compete for clients, compare professional competence

Question 32

Three regulatory documents

Answer 32

HPA Opticians Regulation Standard of Practice Code of Ethics

Question 33

Local optician association

Answer 33

(OABC) Opticians Association of BC

Question 34

National optician association

Answer 34

(OAC) Opticians Association of Canada

Question 35

What do the national opticians association do?

Answer 35

OAC looks out for the interest of opticians

Question 36

Authorization document

Answer 36

Rx for glasses or an assessment record

Question 37

Assessment record

Answer 37

record produced by an independent automated refraction

Question 38

Prescription

Answer 38

authorization to dispense a vision appliance

Question 39

Automated refraction

Answer 39

refraction for assessing visual acuity, using computerized components

Question 40

Independent automated refraction

Answer 40

automated refraction conducted without the involvement of a prescriber

Question 41

Eye examination

Answer 41

includes both eye health assessment and refractive error assessment, conducted by an optometrist or ophthalmologist

Question 42

Refraction

Answer 42

when light travels from one medium into another the path of light ray will be diverted

Question 43

Reflection

Answer 43

when light changes direction as result of "bouncing off" a surface like a mirror

Question 44

Index of refraction (RI) formula

Answer 44

RI = Speed of light in air / speed of light in new substance

Question 45

What are the units for focal length?

Answer 45

Unit is in Metres

Question 46

What are the units for power?

Answer 46

Unit is in Diopters

Question 47

The visible spectrum is only a small part of the larger ____ spectrum.

Answer 47

Electromagnetic

Question 48

A wavelength is measured from ______.

Answer 48

Crest to crest

Question 49

Parts of a wavelength

Answer 49

Crest = top /\ trough = bottom \/ wavelength measured = crest to crest amplitude measured = crest to trough

Question 50

Prism bends light towards ___

Answer 50

the base

Question 51

Prism displaces image towards ___

Answer 51

the apex

Question 52

Meibomian

Answer 52

eyelid glands that create the lipid layer of the tear film

Question 53

Horizontal Visible Iris Diameter

Answer 53

Size of the average iris (~12mm) | Size of the average eye (~24mm)

Question 54

Lid margin

Answer 54

flat part of the lid that meet when your eyes blink

Question 55

Caruncle

Answer 55

sweat and oil glands for the tears

Question 56

Plica semilunaris

Answer 56

fleshy tissue beneath the caruncle

Question 57

Palpebral Fissure

Answer 57

distance between the upper and lower lids

Question 58

3 tear film functions

Answer 58

1. forms a smooth refractive optical surface 2. maintains a moist environment of the epithelium 3. carries oxygen to the eye

Question 59

5 steps that tear flow

Answer 59

1. secretions from the lacrimal, meibomian and conjunctival goblet cells are distributed onto the cornea 2. secretions separate to form the 3-tier film layer 3. With each blink, tears are directed towards the nasal canthus and into the puncta 4. Afterwards, tears flow through the canaliculi to the lacrimal sac 5. tears drain through the nasolacrimal duct and into your nose

Question 60

5 angle structures for proper aqueous humor outflow to prevent glaucoma

Answer 60

1. root of the iris 2. ciliary body 3. scleral spur 4. Schlemm's Canal 5. Trabecular Meshwork

Question 61

Standards of Practice guidelines DO

Answer 61

- represent COBC view of what "good practice" means - serve as a guide as to the scope of services that the optician can provide - represent what a competent optician is able to do in practical and achievable terms

Question 62

Standards of Practice guidelines DO NOT

Answer 62

- constitute a checklist of clinical or professional procedures that must be performed - indicate what opticians must do in a given set of circumstances