Designer Sunglasses

[Autos Pak]

Excessive sunlight is harmful for eyes so sunglasses have been
especially designed for this purpose. It helps in protecting the eyes
as they are the most sensitive area of our body. Tissues of eyes can
be easily destroyed by the continuous and overexposure to the sunlight
radiations which are visible or non visible in the spectra. Bright
sunlight is usually very distracting and annoying but overtime
exposure can cause headaches or sore eyes while also may cause
permanent damages to the retina, lens or cornea. Temporary damages of
overexposure may result into reduction in vision called snow
blindness. Permanent effects include cataract eyes or even the loss of
night vision. So hence it is proved that the damage is caused by the
ultraviolet (UV) rays which is harmful and burns the surface of the
cornea.
Basic idea kept in mind while inventing the sunglasses was to help in
reducing distracted glares and giving comfortable view and reading in
the bright light. Initially, sunglasses had simple tinted glass or
plastic which were only helpful in reducing the brightness. So, darker
lenses were considered better as they screened out the more light. As
soon as we got knowledge about the harmful reaction of ultraviolet
rays of sunlight, we knew there is definitely a need of better type of
glass to be used in sunglasses for the protection of our eyes.
Technology jumped from the inexpensive models which were made of
plastic lens and frames to costly ground glass lenses. Famous brands
used this new technology with the custom-made frames; sunglasses were
then available in astounding array of styles and costs. Unfortunately,
there is only no way to know if the lens really gives a protection
from ultraviolet rays by the darkness of the lens.
Raw Materials
Exact definition of sunglasses may be, it consist of two light-
filtering lenses plus a frame which hold them in place. Usually lenses
are made of colored plastic, like polycarbonate etc. Whereas, glass
lens is consider as the high quality branded version of sunglasses.
The premier excellence of lens are optically perfect and which don’t
distort shapes or lines. For example, camera lenses are made up of
distortion free ground and polished optical glass. The scratch
resistant glass is known as borosilicate which is made after the
tempering it with different chemical treatments……..
Reference:
http://www.modsunglasses.com