details about Tinted lenses

2. -An absorptive lens is one that is used for
the specific purpose of reducing the amount
of transmitted light or radiant energy.
-It acts as a filter.
-Absorption may be uniform or selective.
-Some lenses absorb mostly in IR region of
spectrum. Eg Ray Ban.
-Other absorb in UV region. Eg UV 400, UV
420

4. Types of Absorptive Lens
Photochromatic
Lens
Polaroid
lens
Tinted
Lens

5. Natural vision and natural colour perception,
even in glaring and diffuse light. Increased
contrast perception for a pleasant vision
experience. Ideal in road traffic, sports,
nature or on the job. Full UVA, UVB and glare
protection.

6. - Some Lenses are tinted by adding a substance
such as a metal oxide to the lens material when
the lens is being created.
- Tints can also be applied to the surface of a
lens.
- Surface application allows a wide variety of
tints and creates a uniform darkness across the
entire lens, regardless of prescription strength. -
- Modern technology has greatly increased the
toughness of surface lens treatments.

8. Colours Metallic oxide
Green Iron, chromium
Pink Manganese, Didymium
Blue Cobalt
Pinkish brown Cerium
Brown Nickel
Yellow Uranium, Silver,
Kalichrome
Red Gold

9. Variable
Tint
Fixed Tint

10. Plastic lenses are tinted by dipping them in
a solution containing the appropriate
organic dye.
The resulting density depends on the
nature of the dye and the length of time
the lens is immersed in the solution.
If the tint is too dark, for any reason needs
to be changed, some tint can be removed
by dipping the lens in a bleaching solutions.

12. Advantages
The dye penetrates the surface layer of
the lens to a uniform depth hence lenses
are of uniform density independent of
thickness and the prescription.
Any colour
possible
Some tinted can be removed or re-tinted
according to the customers need by
treating the lens with a bleaching solution.
Very easy
Process

13. Disadvantage
The colour of dyed
plastic lenses is not
as stable as in glass
lenses.
Lens Fade
with
time.
Proper tint
involves trial,
error and lots of
experience.
Much of
Infrared light
is transmitted.

14. Various Metal oxides added to the basic batch
materials to impart specific lens colour.
Absorbs selected parts of the spectrum.
Colour distributed evenly all over the lens.
The principle ingredients of white ophthalmic
crown glass are silica, soda lime to which small
amount of potassium, aluminium and barium
oxide are added to provide the desired physical
and chemical properties.

15. They can be produced
in large quantities at
low cost.
The transmission is
affected very little by
surface scratches.
There is absence of
reflections.
No special
equipments is needed
for surfacing and
finishing the lenses.
Advantages

16. Variation in transmission
from center to edge( for
lenses of high power) no
equi tint.
Tint is permanent.
Variation in transmission
from one eye to the other
for patients with large
amount of anisometropia.
Bifocal segment is clear.
Disadvantages

17. A lens is tinted by depositing a thin metallic
oxide on the surface of the lens.
The coating is deposited on the lens by an
evaporation process conducted under a
vacuum at high temperature.
The density of coated lens depends on the
thickness of the metallic oxide.
The coating is deposited on the back
surface of the glass.

18. Only for glass
To reduce the amount of reflection
by the coating, ARC should be done
Tint can vary with improper handling,
scratches on the surface and general
wear and tear.
Possible to have
equi tint lenses
in any
prescription

19. Resin lenses can be tinted by immersing in a
container of dye.
Red, Yellow, blue are three primary dyes from
with which almost all other colours can be made.
The dye can be purchased either in powder or
liquid from which are then mixed with previously
boiled water.
The longer the lens remain in the dye, the more
dye will be absorbed.
Dye tint are not affected by the power of the lens.

20. In addition to colour, the intensity or darkness of
a tint must be specified. It is expressed in
percentage of light it blocks.
Fashion tints are usually in 10-20% range.
Sunglass tint should be atleast 60% intensity to
provide adequate protection.
For most of outdoor activities and daytime
driving 70-80% works well.
For sports like mountain climbing or snow skiing,
90% tints and above are recommended.

22. Tints are also described using “1 to 4”
numbering system instead of percentages
for darkness ratings.
Number one is almost clear……number four
is darkest.
Sunglasses are usually produced in darkness
number three.
Darkness number four is too dark for most
wearers, but can be an ideal choice for high-
glare environments like mountain climbing.

23. Because white light is made up of many colours ,
picking tints carefully can improve the performance
of your eyewear in specific environments and
activities.
ROSE TINT YELLOW TINT
BROWN AND AMBER TINT
GREEN TINT GREY TINT G-15
GRADIENT TINT
DOUBLE GRADIENT TINT
PURPLE
BLUE

24. Cosmetically appealing, soothing to the
eyes, and seems to provide a degree of
relief when the wearer is working in
brightly lit offices. A rose tint is often
recommended for computer users to
help reduce eyestrain and glare.
Advisable for those having colour vision
deficiencies.
ROSE TINT

26. Objects appear sharper against a blue or green
background. Blue light bounces or scatters the
most and can create a kind of glare known as blue
haze . Yellow tints are sometimes marketed as
blue blockers because they are fairly opaque to
blue light.
Good for overcast, hazy or foggy conditions and
are favourite of shooters, skiers and pilots.
Generally not a good choice for any activity that
depends on accurate colour perception.
YELLOW TINT

28. Work well in variable light conditions and
provide good contrast because they filter
some blue light, although not as strongly as
a yellow tint.
Brown lenses are good general purpose
lenses and work especially well for sports
where judging distance is important like
tennis and golf.
BROWN AND AMBER TINT

30. Filter some blue light and enhance
contrast in low-light conditions. The
human eye is most sensitive to green
wavelengths of light so green tints
offer the highest contrast and
greatest visual acuity of any tint.
GREEN TINT

32. Provides good protection from glare
and keeps distortion of colours to a
minimum. Sometimes referred to as tru-
colour tint. Available in a wide range of
densities and is an excellent choice for
general use and driving. Most popular
sunglass tint.
GREY TINT

34. This sunglass tint is sometimes
called the Ray-Ban tint.
Essentially a combination of grey
and green tint that transmits 15%
(blocks 85%) of the light.
G-15

36. Balanced colour which
provides natural colour
perception while shading
the eye. Can be a good
choice for hunters.
PURPLE

38. Can be a good choice for fashion
tints in lighter shades. If the lenses
are intended for outdoor use,
remember that blue tints can
increase glare . In this case, consider
using a brown or grey lens
combined with a blue mirror
coating.
BLUE

40. Describes a lens with a darker tint at the top,
fading gradually to little or no tint at the bottom
of the lens. This provides additional protection
from light coming from above, without blocking
too much light from straight ahead or below.
Gradient sunglasses work particularly well for
driving; glare coming through the windshield is
blocked but the speedometer and other
instruments are easy to see through the lighter
bottom portion of the lens.
GRADIENT TINT

42. Describes a lens with a darker tint at the
top and bottom of the lens and a
medium tint in the center of the lens.
Double gradient tints are good for
skiers, because glare coming from
above (sun) and below ( snow) is
heavily blocked but a clearer viewing
area is present in the middle of the lens.
DOUBLE GRADIENT TINT

44. A commonly occurring situation that
demonstrates the hazards of too much tint for
existing conditions is night driving. At night with
eyes adapted to a light intensity of 0.1 mL
through a clear glass windshield, the visual acuity
of an individual who normally sees 20/20 will be
reduced to 20/32. this is not because of looking
through the windshield, but rather is simply a
result of reduced illumination.

45. Any tinted material between the observer’s
eye and the object being viewed will further
reduce acuity. Even an 82% transmitting pink
tinted lens worn at night reduces acuity to
20/40. a green tinted windshield by itself
reduces acuity to 20/46. the combination of
tinted windshield and tinted lens, however
reduces acuity to 20/60.the level of tint
desirable is therefore a function of the
circumstances under which it is to be worn.

47. The three
major
companies:
ZEISS
ESSILOR
HOYA

48. Do as directed:
1. Tinting of lenses________ the transmittance.
a. Increases b. decreases
c. Normal d. None
2. _______ tint is advisable for use by those having
colour vision deficiencies.
3. The other name for yellow tint is____________
4. Yellow tint help night driving because they eliminate
blue haze. True or False.
5. ________ tint is advisable for night driving.
6. ________ tint have a uniform transmission across the
visible spectrum.
7. Colour of Kalichrome is…………….

49. 8. The tint may be removed and reapplied for…….. type of lenses.
9. Matching:
i) Light pink a) Blue absorbing
ii) Grey b) Highest transmission of visible
light found in the
middle of the visble spectrum.
iii) Green c) even absorption across the
visible spectrum
iv) Yellow d) good for colour defectives.
10. The tinting of lenses being denser in upper part and lighter in
lower part, these lenses are known as.............
a) Photochromatic Lenses b) Isochromatic
lenses
c) Gradient lenses d) None
11. Short note on tinted lens? (12 marks)
12. Explain various methods of tinting in detail? (10 marks)

50. 13. Important properties and uses of following
tints? (7marks) (repeated )
Green, Yellow, Pink and Grey Tint.
14. Define gradient tint?(1 marks)
15. Explain tinted lens. Describe their principle
characteristics of each group.( 10 marks)
16. Explain in detail tinted lenses?(10 Marks)
17. Explain solid integral tint, Green, Yellow, tint
with its advantages and disadvantages.
(10 marks)

51. 1. b) decreases
2. Grey tint
3. Kalichrome
4. False
5. Grey
6. Rose
7. Yellow
8. Vacuum coated or plastic lenses.
9. i – c, ii – d, iii – b, iv - a
10. c) Gradient lenses