Ophthalmic Optics

Front 1

Whats the most common eye problem associated with radiation therapy?

Back 1

Cataract

Front 2

T or f: if the patient is phakic, UV light will not get to their retina

Back 2

T

Front 3

Transmission for _____ wavelengths decreases with age

Back 3

Shorter

Front 4

What are the four effects of UV radiation on the conj/cornea?

Back 4

Photokeratitis, pterygium, pinguecula, climatic droplet keratopathy

Front 5

Corneal opacity, iris changes, cataract and solar retinopathy are all adverse effects of being exposed to what?

Back 5

IR radiation

Front 6

Lenses with a ____ index have more need for AR coating due to the increased reflections

Back 6

Higher

Front 7

T or f: smaller indices of refraction have higher transmission

Back 7

T

Front 8

List in order of most to least UV protection: cr39, polycarb, crown glass

Back 8

Polycarb> cr39> crown glass

Front 9

A ____ colored lens transmits more red than anything else.

Back 9

Red

Front 10

What do photochromic lenses respond to?

Back 10

UV and short visible light

Front 11

Photochromic lenses: darkening rate is _____ dependent

Back 11

Temperature

Front 12

Polarizing lenses: filter placed ____ so _____ polarized light is blocked

Back 12

Vertical; horizontal

Front 13

What's the disadvantage of polarized lenses?

Back 13

Delamination

Front 14

T or f: an AR coated lens (cr39) does not increase transmission evenly across the spectrum

Back 14

F

Front 15

What tint causes the least amount of color distortion?

Back 15

Neutral grey

Front 16

T or f: Medium to dark grey tint is sufficient to act as sunglasses

Back 16

F!! No UV protection with grey tint

Front 17

What tints are good for driving in fog/ haze?

Back 17

Warmer colors: brown, amber, yellow (get rid of shorter wavelength light which scatters more)

Front 18

Do brown lenses absorb any UV?

Back 18

Yes

Front 19

What tint improves cosmesis and helps those who are sensitive to fluorescent lighting?

Back 19

Pink

Front 20

What color is Soft lite tint?

Back 20

Pink

Front 21

What lens tint provides excellent UV protection?

Back 21

Yellow

Front 22

T or f: wearing blue lenses to drive is good for minimizing scatter due to fog and haze

Back 22

False! Dangerous for driving bc it absorbs red

Front 23

What tint color is good for blast furnace workers?

Back 23

Blue (gets rid of IR) (actually any color in the cooler part of the spectrum...violet, blue, blue-green)

Front 24

T or f: every color except grey selectively absorbs/transmits

Back 24

T

Front 25

For welding lenses, the shade number ____ with increasing absorption.

Back 25

Increases

Front 26

Sunglasses in bright conditions should transmit ___-____%

Back 26

10-20

Front 27

ANSI standards:
1. General purpose: ___% transmittance
2. Cosmetic: ____% transmittance
3. Special purpose: ____% minimal transmittance (3-7%)

Back 27

1. 8-40%
2. > 40%
3. 3% minimal

Front 28

Lenses with transmittance < ___% shouldn't be used for driving

Back 28

8

Front 29

T or f: in general, glass lenses filter more UV than plastic lenses

Back 29

F...other way around

Front 30

The intensity of the reflected light ____ as the index of refraction increases.

Back 30

Increases

Front 31

What can solve all 5 types of reflection?

Back 31

AR coating (not BC, VD, PT, smaller lens)

Front 32

T or f: AR is. Placed on both sides of the lens

Back 32

T

Front 33

What are the two conditions an effective AR coating must meet?

Back 33

Path and amplitude (principle of interference)

Front 34

_______ condition: the 2 reflective waves must be of equal intensity. What is the equation accompanying this?

Back 34

Amplitude. Ncoating=Nlens (square rooted)

Front 35

_____ condition: the 2 reflective waves must be 1/2 wavelength out of phase. What is the equation accompanying this?

Back 35

Path. Wavelength/4 is optical thickness. Wavelength/4(Nc) is the physical thickness

Front 36

T or f: the index of the coating will always be. Larger than the index of the lens

Back 36

F

Front 37

If the AR coating is too thin, what color will appear?

Back 37

Amber (pale blue= thick)

Front 38

Multiple coatings give ____ reflections and _____ transmission.

Back 38

Less; more

Front 39

Anisometropia is said to exist when the _________ refraction of. The two eyes differs by _____D or more.

Back 39

Spherical equivalent; 1.00

Front 40

Greater than ___D of vertical prism can cause symptoms.

Back 40

1

Front 41

Who is more at risk for vertical vergence problems?

Back 41

Presbyopes

Front 42

If you are going to prescribe dissimilar segs in a pt with +4 and -1, what lens would you give the ultex A and executive bifocal to?

Back 42

Ultex A for the more plus lens (has tons of BD) and executive goes to the minus lens (minus lens has BD and this gives BU)

Front 43

Slab off removes ___ prism. So, what lens gets this? Plus or minus?

Back 43

BD; minus (reverse slab off removes BU)

Front 44

What are the two most common ways to correct vertical prism?

Back 44

Slab off, contact lenses

Front 45

Image size differences of ___% give the most frequent complaints.

Back 45

1-2.5

Front 46

What are the top two symptoms of aniseikonia? What's the least common symptom?

Back 46

Asthenopia, headache; spatial distortion

Front 47

Who has the larger uncorrected RIS? Axial myope or axial hyperope?

Back 47

Axial myope

Front 48

T or f: the shape factor is the one with the magnifying power

Back 48

T

Front 49

T or f: the power factor has magnifying and vergence power

Back 49

F!! Only vergence

Front 50

T or f: the shape factor involves base curve and thickness while the power factor involves vertex distance and back vertex power

Back 50

T

Front 51

About 2D of difference in Rx between the eyes gives about a ___% magnification difference

Back 51

2

Front 52

Minus lenses moved away from the eye give ____ (more or less) magnification.

Back 52

Less (plus=more)

Front 53

The retinal image is _____ in the direction of the axis of the minus cyl.

Back 53

Larger (minus minifies)

Front 54

What type of anisometropia will not give aniseikonia with spectacles but will give it when uncorrected or fitted with contact lenses

Back 54

Axial ametropia

Front 55

What does knapps law say?

Back 55

Give spectacles to axial ametropes and contact lenses to refractive ametropes.

Front 56

Astigmatism is generally _______ (axial or refractive).

Back 56

Refractive

Front 57

What does not fit in this sequence: space eikonometer, A scan, keystone orthoscope, leaf room.

Back 57

A scan (which evaluates refractive or axial....the other are ways to detect and measure aniseikonia)

Front 58

What are iseikonic or eikonic lenses used for?

Back 58

Minimize or eliminate aniseikonia

Front 59

How do you. Increase the magnification of a plus lens in eikonic lenses?

Back 59

Increase: front curve, thickness, vertex distance

Front 60

In eikonic lenses, what do we focus on? Shape or power mag?

Back 60

Shape