Page 11 - NAME OF CONDITION: REFRACTIVE ERRORS

Hi Index Lenses
For a high myope heavy, thick ringed lenses make their eyes seem small and unsightly. An

excellent alternative are hi-index lenses that give the same refractive power at half the
thickness of the normal glass lens. These are available in both plastic and glass lenses.
Lenses admit most of the light through them – but some of the incident rays are reflected

off the surface of the lens. This causes glare, which is disturbing when driving in the night
with glasses on or while using the computer.

Anti-Reflection Coatings (or ARC) that is applied onto the lens ensures that the lens admits
up to 99% of the light. This not only gives clearer vision to the wearer, it is a cosmetically
better choice as the ugly reflections on the lens surface are avoided and the eyes are visible
to the onlooker.

Correction for Presbyopia
Presbyopes require glasses called bifocal lenses (two focal lengths); their main
disadvantages being discomfort if line of sight falls at the division in the lens; and being
able to see clearly only at two focal lengths.

To help them focus at all distances new lenses have been designed called ‘varifocals’.
These are designed by increasing the focal power gradually (so also called Progressive
Addition Lenses). They eliminate the discomfort caused by segments in the lenses and
improve the quality of vision.
Safety Lenses
These are special eyewear systems designed for protecting the eye from excessive heat,
dust, light, harmful rays, or impact. This eyewear is suitable for people working in extremes

of environment like welders, bikers, those living in extremes of weather, those handling
harmful chemicals etc.

Polarized lenses have long been known and proven to enhance visibility and reduce glare
under all conditions. The lenses provide a sharper vision under any environmental
condition. Polarized lenses are the only lenses that provide visibility below the surface of
the water in a marine environment. A polarized lens filters and eliminates annoying glare
and transmits only efficient light to the eye. Wherever there are horizontal surfaces
producing glare, the use of polarizing lenses is recommended because it reduces eye
fatigue and maintains the health of your eyes while exposed to the sun.

Ultra Violet Protection
UV Filter capacity of a lens is measured and certified. Lenses marked UV400 mean that they
block 100% of UVA & UVB. As a result, your eyes are not subjected to any harmful rays. All
sunglasses offer UV protection to some extent but not 100%. Exposure to UV rays

accelerates development of cataract, degeneration of cornea and retina. It can also cause
tumors of the eyelid.

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