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O Optics B11 > Tints And Coatings > Flashcards

Tints And Coatings Flashcards

1
Q

Coating that repels water, preventing the formation of water spots

A

Hydrophobic coating

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2
Q

Coating that resists smearing from facial or skin oils, smudge resistant. Also called lipophobic

A

Oleophobic coating

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3
Q

Coating that reduces attraction or dust (dust repellent)

A

Anti-static

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4
Q

Coating that eliminates the condensation of moisture on lenses that cause fogging (when coming in from the cold)

A

Anti-fog

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5
Q

Fog free coating that is applied to lenses before they are cut to a frame

A

Opticote

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6
Q

Who would want anti-fog lenses?

A
  • skiers
  • police officers
  • first respondents
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7
Q

A coating applied to a lens that does not interfere with how the lenses function, but creates a permanent bond with the lens that reduces the incidence of the hairline scratches common to plastic
lenses

A

Scratch resistance

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8
Q

What is the different between glass lenses and plastics regarding scratch resistance?

A

Glass lenses are scratch resistant, but plastics are fragile and need scratch resistant coating

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9
Q

Can a coating be applied to a lens to make it scratch proof?

A

No!

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10
Q

When a lens is immersed in a bath of coating solution

A

Dipping

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11
Q

A liquid coating dropped on the center of a surface and rotated rapidly

A

Spin coating

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12
Q

How is scratch resistance applied?

A

Be dipping or spin coating

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13
Q

After coating what must be done to strength en adherence and promote durability?

A
  • baking

- UV curing

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14
Q

A thin layer or series of layers of material applied to the surface of a lens for the purpose of reducing unwanted reflections from the lens surface and thus increasing the amount of light that passes through to the eye

A

Anti-reflective coating

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15
Q

What are 4 benefits of an anti-reflective coating?

A
  • better light transmission
  • better vision in all lighting situations (especially low light)
  • reduces eye strain
  • cosmetic benefits
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16
Q

The higher the index of refraction, the ___ light that will be reflected from the surface

A

More

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17
Q

A/R coatings usually consist of multiple microscopic layers of____

A

Metallic oxides

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18
Q

Why do we use multiple layers for A/R coatings?

A

Because the more layers, the more reflections that are neutralized

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19
Q

Are A/R coating lenses thick or thin? Are they uniform or uninformed?

A

That are microscopically thin and uniform layer

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20
Q

A multilayer A/R coating stack generally is about ___ microns thick

A

0.2-0.3

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21
Q

What 2 faint residual colors are A/R coatings usually?

A

Green or blue

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22
Q

In general, lenses transmit ___ of available light to the eye–> A/R coated lenses can transmit up to ___ of light through the eye

A

General: 85-96%

A/R: 98-99.5%

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23
Q

In what type of lenses do you want to make sure they have an A/R coating?

A
  • polycarbonate
  • high index lenses
  • aspheric lenses
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24
Q

T/F: blue light can be harmful on the eyes

A

True

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25
Q

What eye disease is blue light a risk factor to?

A

Age-related Macular degeneration

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26
Q

T/F: A/R coatings cant filter out harmful blue light

A

False. They can

27
Q

Used to block UV rays from damaging the eye

A

UV coating

28
Q

What is considered a good UV coating?

A

Less that 5% of UV rays pass through the lens (95% blocked)

29
Q

What is considered the best UV coating on a lens?

A

2% or less of UV rays pass through the lens (98%blocked)

30
Q

What is the wavelength of UVA?

A

320-400nm

31
Q

What is the wavelength of UVB?

A

290-320nm

32
Q

What is the wavelength of UVC?

A

100-290nm

33
Q

What is the worst UV light?

A

UVC

34
Q

All of the common lens materials absorb what type of UV light?

A

UVB

35
Q

What 2 lenses absorb all UV radiation?

A

Polycarbonate and trivex

36
Q

Lenses that darken on exposure to light, most commonly UV radiation

A

Photochromic lenses

37
Q

formulation of dyes on the surface of the lens that are

made up of molecules that constantly recalibrate as light changes

A

Transitions Chromea7

38
Q

What 2 ways can transitions chromea7 be added?

A
  • imbibing (uses head to draw dye into lens)

- trans-bonding (puts on lens surface)

39
Q

What are 4 problems of photochromic lenses?

A
  • car windows block nearly all UV
  • temperature dependent (darkens less in higher temp and more in the cold)
  • red light infrared radiation makes the lens return to tits lighter state (darken more skiing, less at the beach)
  • takes longer to fade when going indoors
40
Q

T/F: photochromic lenses block 100% of UV rays without the need for an added UV lens treatment

A

True

41
Q

T/F: A/R coatings enhance visual clarity and comfort without reductions sun-reactive performance. They can also increase the sensitivity and decrease reaction time

A

True

42
Q

Lenses that have optimal balance between darkness, clarity, and feedback speed (darken in random patterns)

A

Transitions signature

43
Q

Lenses with variable polarization as lens darkens (darken and align)

A

Transitions vantage

44
Q

Transitions with the darkest lenses, even at high temps. They respond to UV and natural light

A

Transitions XTRActive

45
Q

Transitions that are polarized and the color and density change in brighter conditions. Low light levels (green/yellow) and higher light levels (dark red/brown)

A

Transitions DriveWear

46
Q

Mirror coating with a hint of color

A

Flash mirror

47
Q

Mirror coating can absorb from __ more light than non-mirrored surfaces

A

5-65%

48
Q

Mirror coating with high density of color, and a higher % of reflectance

A

Solid mirror

49
Q

What are some pros of mirror coatings?

A
  • reduces glare
  • easy to clean
  • repeals minister, fingerprints, and smudging
50
Q

Tints darker than ___ should be avoided

A

8%

51
Q

Worn for cosmetic appeal, visual comfort, protection, or all 3

A

Sunglasses

52
Q

Lenses that reduce the intensity of light reflections

A

Polarized lenses

53
Q

Who are some people/activities that would want polarized lenses?

A
  • fishing
  • driving
  • golfers
  • cyclists
54
Q

What are some cons regarding polarized lenses?

A
  • reduces ability to identity changes in terrain or identify ice
  • changes brightness of snow so it can be dangerous and nauseating for skiers
  • can wash out texture of grass making greens difficult to read
  • commercial pilots
55
Q

Tints that are consistent in color and depth over the entire lens

A

Solid tints

56
Q

Tints with variable color throughout the lens

A

Gradient tints

57
Q

Contains two tints that is darker on the top and lighter at the bottom

A

Double gradient tints

58
Q

How is glass tinted?

A

By mixing metals directly into the glass

59
Q

How is CR39 tinted?

A

Can be dipped into a solution that dyes lenses

60
Q

The longer the exposure to a dye, the ____ the tint (CR39)

A

Darker

61
Q

A lens where its impervious to duke so the scratch resistant coating is dyed instead

A

Polycarbonate

62
Q

Is trivex tintable?

A

Yep

63
Q

In hi index lenses, tinting is ___ and can require special processes

A

Slow

O Optics B11 (4 decks)

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