2. INTRODUCTION
• TINT MEAN COLOUR LENSES.
• TINTED LENSES WAS PURPOSE IN 1980.
• TINTED LENSES ARE WORN IN GLASSES OR
CONTACT LENSES.
• TINT IS A ABSORPTIVE LENS.
• TINTED LENS IS ALSO KNOWN AS ‘COSMETIC
LENS’.
2
3. ABSORPTIVE LENSES
• AN ABSORPTIVE LENS IS ONE THAT IS USED
FOR THE SPECIFIC PURPOSE OF REDUCING
THE AMOUNT OF TRANSMITTED LIGHT OR
RADIANT ENERGY.
• IT ACT AS A FILTER.
• ABSORPTION MAY BE UNIFORM OR
SELECTIVE.
3
5. • Tints and coating used on spectacle lens
Serve a fashion purpose can make vision
More comfortable, can improve visibility
And contrast and can protect the eye
from effects of harmful radiations.
5
7. INTEGRAL TINT
• IT IS ALSO CALLED TINTED SOLID GLASS
LENSES.
• ONE OR MORE METALS OR METALIC OXIDES
ARE ADDED TO THE BASIC BATCH AT THE TIME
OF MANUFACTURING.
• THEY PROVIDE THE DESIRED PHYSICAL AND
CHEMICAL PROPERTIES.
7
8. • The principal ingredients of white ophthalmic
crown glass are silica , soda & lime to which
small amount of potassium , aluminum &
barium oxides are added to provide the
desired physical & chemical properties
8
9. • To produce a tinted lens , one or more metals
or metallic oxides are introduced into the
basic batch at the star of the process ( less
than 1 % )
• Iron = green
• Cobalt = blue
• Gold = red
9
11. Advantages :
- 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
& finishing the lenses
11
12. • Disadvantages :
- Variation in transmission from center to edge
( for lenses of high power ) no equi tint.
- Variation in transmission from one eye to the
other for pts with large amount of
anisometropia
12
14. Surface coating
• A lens is tinted by depositing a thin metallic
oxide on the surface the lens
• The coating is deposited on the lens by an
evaporation process conducted under a
vacuum at high temp
• Because of high temp , the process can not be
used with plastic lenses
14
15. • The density of the coated lens depends on the
thickness of the metallic oxide
• The coating is deposited on the back surface
of the glass
• To reduce the amount of light reflected by the
coating , an AR coating is placed on the
metallic oxide coating
15
17. • Disadvantages
- only for glass
- ARC should be done
- Tint can vary with improper handling
, scratches on the surface & general wear &
tear
17
18. DYE TINT
• Resin lenses can be tinted by immersing in a
container of dye.
• Red , yellow , blue are the 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.
18
19. • 92 to 96c temperature
• The longer the lenses remain in the dye , the
more dye will be absorbed.
• Dye tint are not affected by the power of the
lens.
19
20. Tinted plastic lenses
• 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 & the length of time the lens is immersed in the
solution
• If the tint is too dark , or for any reason needs to be
changed , some tint can be removed by dipping the
lens in a bleaching solutions
20
22. • Disadvantages
- Glass lenses can not be done
- Fades faster
- Proper tint involves trial , error & lots of
experience
22
23. -The color of dyed plastic lenses is not as stable
as in glass lenses
-Most dyed lenses fade with time
-Same material from different manufacturing
batch absorbs dye at dis-similar rates
-An old lens may not tint same as a new one
23
24. YELLOW TINT
• IT IS ALSO CALLED ASKALICHROME
• CHROMIUM OR SULPHAR OXIDES ARE USED
TO GIVE RISE TO YELLOW TINT FILTER.
• SOME TIME URANIUM OXIDES CAN ALSO
USED.
• IT ABSORB SHORT VISIBLE WAVE LENGTH.
• THESE LENSES ARE TRADITIONALLY USED AS A
SHOOTING GLASS.
24
25. • YELLOW FILTER ABSORB BLUE,VIOLET AND UV
LIGHT WHILE ALLOWING A LARGER
PERCENTAGE OF OTHER FREQUENCIES
THROUGH.
• CONTRAST ENHANCE
• CAR DRIVING
• SKIING
25
26. RED TINT
• MATERIAL IS SELANIUM.
Red tint can be helpful for hue discrimination
colour deficiency.
a) skiing.
a) hunting.
b) sharply defind contrast.
26
27. PURPLE TINT
• Allows 70 % of visible light transmittance
inside and 20 % outside
• Provides a natural color perception while
shading the eye
28. GREY
• Called as NEUTRAL LENS
• Most popular for sunglasses
• Evenness of transmission through whole
visible spectrum
• Allows colors to be seen in there natural state
relative to one another
• Thus satisfactory for use in color deficient
29. 1. Protection tint.
2. Reduce the intensities.
3. Protection against glare.
4. Driving
29
30. • For sun protection
• Colour vision deficiency
• Fishing
• Boating
• Driving
30
31. BLUE
• Also called as alpha
• Used in aphakics to reduce glare problems
• Also to absorb the blue end of the spectrum
which is the property of the lens
• Small concentration of cobalt yield blue glass.
• Blue tint is not advisable for outdoor work.
33. GREEN TINT
• Material is ferrous oxide metal.
• It is also called as colobar.
• Transmission curve closely approximates the
color sensitivity curve of the human eye
• Earlier popularly used in Military & Pilots
• There is good absorption of UV and IR rays
33
35. PINK TINT
• Pink is an example of unsaturated red.
• Cerium is added to the batch mix to give rise
to pinkish tint.
• Is is also called as sweetest colour.
• Pink may be the colour of choice when there
is some neurological problem.
• Give for indoor work.
35
37. • Used for unfavorable indoor lighting
situations and best solution for
problems such as change in lighting
• It absorbs ultraviolet radiations
37
38. BROWN TINT
• Brown tint is good general purpose filter.
• Absorbs blue end in higher proportion than
yellow
• Commonly used to improve contrast on
bright, hazy and smoggy days
• It is an excellent contrast enhancing filter & is
very much suitable for sun protection.
• It is an ideal tint for drivers for day time.
38
39. G 15 TINT
• A combination of both gray and green
• Good option for sun glasses
• Reduce glare
• Reduce eye strain in bright light
