Sunglasses

SUNGLASSES

MADE BY : AMAN PATHAN

FROM : BHARTIMAIYA COLLEGE OF OPTOMETRY

TODAY WE ARE SEEING……..

(1)INTRODUCTION(2)HISTORY(3)IDEAL PROPERTIES(4)OTHER NAME(5)STANDARD(6)CONSTRUCTION(7)FUNCTION (8)USES(9)ADVANTAGE & DISADVANTAGE(10)MAJOR BRANDS

WHAT IS SUNGLASSES???

• Sunglasses is a form of protective eyewear designed primarily to prevent bright sunlight and high-energy visible light from damaging or discomforting the eyes.

• They can sometimes also function as a visual aid, as variously termed spectacles or glasses exist, featuring lenses that are colored, polarized or darkened. In the early 20th century they were also known as sun cheaters.

IDEAL PROPERTIES

• According to pitts and kleinstein the ideal pair of sunglasses should do the following:

(1)Reduce the intensity of sunlight for optimum visual comfort & visual performance.

(2)Eliminate parts of the optical spectrum that are not required for low vision and are hazardous to the eyes.

(3)Resist impact & scratching and only require a minimum of care.

(4) Provide enough protection while being worn during the day so that the wearer’s dark adaptation and night vision are preserved at night.

(5) Maintain normal colour vision and allow the wearer to distinguish traffic signals quickly & correctly.

STANDARD

• There are four categories of sunglasses lenses listed in the ANSI Z80.3-2001 SUNGLASS AND FASHION EYEWEAR.

• According to the ANSI Z80.3-2001 standard, the lens should have a UVB (280 to 315 nm) transmittance of no more than one per cent and a UVA (315 to 380 nm) transmittance of no more than 0.3 times the visual light transmittance.

As of 2009, the European CE mark indicates that the glasses actually offer a safe level of Sun protection

(1) A COSMETIC LENS generally speaking this

lens is more for fashion than function.

Transmission of light is more than 40%

(2)A GENERAL PURPOSE LENS [medium to dark]

This is the category used for sunglasses normally used by most individuals.

Transmission of light is between 8% to 40%

(3)A VERY DARK SPECIAL PURPOSE LENS [VERY DARK]

This lens is appropriate for situations of very intense light , such as for mountain climbing.

Transmission of light is between 3% to 8%.

(4)A STRONGLY COLOURED SPECIAL PURPOSE LENS [ STRONGLY COLOURED]

This type of lens might filter certain spectral colours more heavily than others.

Transmission of light is 3% is minimum.

Sunglass TintsGrey Yellow or

Gold

Amber or Brown

Green

Purple

Grey TintGreat all-purpose tint

Good protection

against glare

Reduces brightness

with the least amount of distortion

Good for driving and general use

Green Tint

Filters some blue light

Reduces glare

Offers the highest

contrast and greatest

visual acuity

One of the most popular

Pink or Rose Tint

Best contrast of objects against a

green or blue background

They make a good choice for

hunting or water skiing

Yellow Tint

Reduces the amount of blue

light

Allows a larger

percentage of other

frequencies through

Makes everything look

bright and sharp

Blue light can create a glare known as blue

haze

Amber or Brown Tint

Like grey, good general purpose tints

Reduces glare

Contains molecules that absorb higher

frequency colors, such as blue and

UV rays

Distorts color like yellow lenses, but increases

contrast and clarity