tinted lenses

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TINTED LENSES

MADE BY: SWATI PANARAFROM : BHARTIMAIYA

COLLEGE OF OPTOMETRY2nd year 3rd semester

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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’.

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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.

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TYPES OF ABSORPTIVE LENS

• (1)TINTED LENS• (2)PHOTOCHROMATIC LENS• (3)POLAROID LENS

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• Tints and coating used on spectacle lensServe a fashion purpose can make vision More comfortable, can improve visibilityAnd contrast and can protect the eye

from effects of harmful radiations.

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CLASSIFICATION OF TINT

Tinted Lens

Fixed Tint

Integral Tint

Surface Coated Dye tint

Variable tint

Glass Organic

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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.

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• 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

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• 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

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• Nickel = brown • Silver = yellow • Cerium = pinkish brown • Manganese = pink • Didymium = pink

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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

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• 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

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- The permanence of the tint ( it can not be removed )

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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

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• 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

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• Advantages - possible to have equip tint lenses in any RX

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• Disadvantages - only for glass - ARC should be done - Tint can vary with improper handling ,

scratches on the surface & general wear & tear

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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.

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• 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.

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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

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• Advantages - very easy process - Any colour possible - Price factor

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• Disadvantages - Glass lenses can not be done - Fades faster - Proper tint involves trial , error & lots of

experience

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-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

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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.

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• YELLOW FILTER ABSORB BLUE,VIOLET AND UV LIGHT WHILE ALLOWING A LARGER PERCENTAGE OF OTHER FREQUENCIES THROUGH.

• CONTRAST ENHANCE• CAR DRIVING• SKIING

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RED TINT

• MATERIAL IS SELANIUM.Red tint can be helpful for hue discrimination

colour deficiency. a) skiing.a) hunting.b) sharply defind contrast.

PURPLE TINT• Allows 70 % of visible light transmittance

inside and 20 % outside• Provides a natural color perception while

shading the eye

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

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1. Protection tint.2. Reduce the intensities.3. Protection against glare.4. Driving

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• For sun protection• Colour vision deficiency• Fishing• Boating• Driving

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.

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USES

1. Boiler tender.2. smelters.3. Foundry work.4. Furnace work

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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

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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.

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• Used for unfavorable indoor lighting situations and best solution for problems such as change in lighting

• It absorbs ultraviolet radiations

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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.

G 15 TINT• A combination of both gray and green• Good option for sun glasses• Reduce glare• Reduce eye strain in bright light

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COMPANY

• ZEISS• TRANSITION• DRIVE WEAR• CARRERA

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Images

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•THANK YOU