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Mirror coatings were
derived as a functional reflective coating to help
redirect sunlight from the surface of lenses. Since its introduction
many derivations of mirror coatings have been produced creating a
wide range of colored mirror coatings and functional purpose.
Different applications have also been introduced creating a
multifunctional purpose and a cosmetic market for mirror
coatings with flash mirror coatings. Below you will find
descriptions of the composition, maintenance, types, and correlation
of mirror coatings with tins and polarized lenses.
COMPOSITION OF MIRROR COATINGS
► Mirror
coatings can be applied to almost any lens materials surface, and
are most commonly applied to the outer surface of the lens.
► Mirror
coatings are applied to lenses by a vacuum application of
interference layers made of powdered oxides, metals, lacquered
plastics or other available compounds.
► Mirror
coatings are composed of constructive interference layers that
interfere with light passing through the lens by reflecting light.
The denser the interference layers the more reflection is induced,
creating a mirror effect.
MAINTAINING MIRROR COATINGS
► Mirror
coatings should be cleaned with specially formulated lens cleaners.
Other commonly used home made solution include:
o A mild soap
(no higher than PH 7.5) diluted in water.
o 70%
isopropyl alcohol diluted in water (no more than 50/50 mix if used
on a regular basis)
► Stay away
from strong detergent soaps and strong acidic or base solutions
(PH’s ranging around 10) including any ammonia based solutions like
Windex or other industrial cleaners.
TYPES OF COATINGS AND PURPOSE:
► Mirror
coatings can be applied as a solid,
gradient and double
gradient coating. Some common mirror coatings include the
“Half Mirror” and “Flash mirror”. The half Mirror Coating is a dense
mirror coating that gives a full mirror reflection on the outer
surface of the lens. This coating completely shields the appearance
of the eye. The flash mirror coating is a less dense coating that
offers a transparent mirror effect.
► Mirror
coatings are used for functional and aesthetic reasons. Functionally
the double gradient mirror coating is used to reflect light from
above and light reflected from the ground while allowing more light
to pass through the center. The combination of a
double gradient mirror coating
and moderately dark solid
tint and/or polarized lens
delivers optimal direct visual acuity on sunny days with snow or
other glare enhancing matter on the ground.
TINTS & POLARIZATION WITH COATINGS:
► Underlying
tints are usually applied prior to applying mirror coatings. These
underlying tints serve as a background enhancing the mirror effect
and also visual acuity if well proportioned. However, because some
coatings like the “half-silver” mirror coatings reflect a good
portion of light away, the darker the tint on the lens the less
light is reaching the eye. Considering that light is one of the main
ingredients to vision, a darker tint may result in too much loss of
light, which can affect visual acuity.
► For the most
reduction of glare a polarized lens
with a mirror coating is recommended. |
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