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Flashcards in Dispensing 1 Deck (48)
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1
Q

what is the role of dispensing optician?

A

.they give advice on frames and lenses and measurements relating to dispensing spectacles
.they can also sepcialise in low vision and contact lenses

2
Q

what must a dispensing optician have?

A

ABDO qualification plus a registration with GOC

3
Q

what are the different types of lenses?

A

.single vision
.bifocal- 2 prescription in one lens
.trifocal-3 prescription in one lens
.progressive power lenses e.g.VARI FOCAL which is no lines on lens
.occupational lenses- type of varifocal e.g for computer

4
Q

what are the types of RX?

A

Rx is either spherical - correct ametropia (myopia and hypermetropia)
Rx could also be cylindrical - correct astigmatism( includes power of cylinder and axis)
Rx could also be used to correct both

5
Q

what are three types of vision prescriptions?

A

.DV - distance
.IV - intermediate e.g mid range of site e.g artist or music notes
.NV- near- tablet and books

6
Q

how is a prescription usually written?

A

sph/cyl X axis

7
Q

what is the axis used to correct?

A

the axis is used to correct astigmatism

8
Q

how does transposition work?

A

.add SPH+CYL to obtain new sph
.change sign of CYL
.add 90 to original axis

9
Q

what is the transposition of -1.25/-2.50 x 40 ?

A

-3.75/+2.50 x 130

10
Q

what are the combination of bifocal prescription?

A

. DV and NV
. DV and IV
.IV and NV

11
Q

what is the advantage of bifocal?

A

allows you to see both reading and distance at same time.

12
Q

what is the disadvantage of bifocal?

A

.change is prescription from distance to reading can cause blur
. stiff neck

13
Q

how does trifocal work?

A

contains all three distances

.DV , IV , NV

14
Q

how does progressive power lens or varifocals work?

A

.contains all three distances
.distance vision is in the upper hemisphere of lens
.there is a small stabilised zone for near vision at the lower edge of lens
.connecting these two areas is a narrow channel with a gradually increasing plus power called progression zone
by lens changing the power has elements of distortion

15
Q

what is the disadvantage of varifocals?

A

blur/stiff neck

16
Q

what is asthenopia?

A

eye pain or ocular fatigue

17
Q

what are some types asthenopia ?

A

.sore eyes
.tired eyes
.eyes pull
.visual discomfort

18
Q

what are some issues that arise during visual display terminals? e.g. looking at computer

A

. blink rate reduces
.eyes tend to get dry
.reduced eyelid coverage

19
Q

how should a workstation setup look like?

A

.adjustable blinds
.screen at 90 degs to window
.screen below eye level
.concealed lighting

20
Q

what are some types of lens coating?

A
. hard coat
. MAR
. tints
. UV
. photochromic
. polarised
21
Q

what is hard coat?

A

abrasion resistant coat

22
Q

what is the advantages of hard coat?

A

. reduces scratches

23
Q

what is the disadvantage of hard coat?

A

. cost

.doesn’t stop all scratches

24
Q

what is MAR coat?

A

.anti reflection coat

.reduces reflection thus better vision

25
Q

what are the advantages of MAR coat?

A

. can help eyestrain and fatigue by reducing unwanted glare/reflection
. good for night driving
. cosmetically better

26
Q

what are the disadvantages of MAR coat?

A

. can look dirtier and smudgier

27
Q

what are the advantages of tints?

A

. reduces squinting in bright light

28
Q

what are the disadvantages of tints?

A

. can reduce VA

. can change the colour of things

29
Q

what is the advantage of blue light?

A

. may improve visual comfort

good for computer use

30
Q

what are the disadvantages of blue light?

A

. can look dirty
. can look quite blue on lens
.can make lenses look yellow
.shorter wave length more damage to the eye

31
Q

what is the function of UV coat?

A

blocks UV light

32
Q

what are the advantages of UV ?

A

. protection from un wanted UV radiation
.reduce risk of cataract
. helps prevent UV damage to skin around the eye

33
Q

what are the disadvantages of UV?

A

can make lens look yellow

34
Q

what is a photochromic light?

A

. a lens that adapts from light to dark and vice versa

35
Q

what is the advantage of photochromic light?

A

. gives patient one pair of glasses

36
Q

what is the disadvantage of photochromic light?

A

. don’t work in cars

. slow to change back

37
Q

what is the advantage of polarised light?

A

.can reduce unwanted glare/reflection on wet surfaces

38
Q

what are the disadvantages of polarised light?

A

.changes the way light is reflected off pavements so makes image look unusual
. can stop you seeing digital screens if light is polarised in a certain way

39
Q

what is inter-pupillary distance?

A

. distance between the centre of the pupils

40
Q

how to measure inter-pupillary distance?

A
  1. make sure your eyes are on the same level as patient
  2. make sure the ruler is held steady on patients forehead
  3. close right eye and direct patient to look into your open left eye
  4. zero the ruler at centre of pupil or edge of pupil or edge of iris
  5. read PD off the scale of the ruler
41
Q

what is average male PD?

A

64

42
Q

what is average female PD?

A

62

43
Q

how to measure monocular pupillary distance?

A

.measure left eye to middle of nose and then middle of nose to right eye

44
Q

when to measure mono PD?

A

. when one eye is closer to nose than the other
. high index lens- too high prescription so you have to thin the lens
.progressive lenses- varifocal lenses
. aspheric lenses- coating that comes with lenses

45
Q

What do we write out for the order for single vision lenses for intermediate prescription?

A

IV= Dv Rx +IV add to spherical part

-axis and cyl stay the same

46
Q

Healthy eye with plenty of accomodation?

A

Dv, Iv and Nv is clear

47
Q

HCL?

A

Bottom of rim to centre of pupil (measure)

48
Q

What do we write out for the order for single vision lenses for near/reading prescription?

A

NV= Dv Rx + NV add to spherical partt