What
About Eyeglasses?
Eyeglasses
are devices for aiding, improving or correcting defective sight. In addition
correcting various eye conditions, eyeglasses are also utilized for protecting
eyes from damage caused by sunlight, ultraviolet light or flying objects. Eyeglasses
typically consist of a pair of glass or plastic lenses mounted in a frame that
sits on the bridge of the nose and is held in place with arms that rest or are
hooked behind the ears.
Eyeglass
lenses, originally made exclusively from glass, have evolved to include high-tech
polymer materials such as CR39, Transitions® (photochromic plastic), Polycarbonate,
and High Index plastic. Lastly, multifocal lenses have been developed which contain
two or more vision-correcting prescriptions in one lens (ex. Bifocals = lenses
split into two sections; the upper part is for distance vision and the lower part
is for near vision, and Progressives = lenses that gradually change prescription
from normal distance vision at the top to intermediate vision (arms length vision)
in the middle to a reading prescription at the bottom. Further, eyeglass materials
have options for individual needs consisting of lens filters that block the
ultraviolet (UV) light, anti-scratch coatings that increase the surface hardness
of lenses (an important feature when using plastic lenses) and anti-reflective
(AR) coatings that eliminate significant glare and allow other people to see
the eyes of the wearer. There is also a full spectum of eyeglass lens tints, from
lighter tints to darker tints, for use in sunglasses.
There
are four vision deficiencies for which eyeglasses can compensate. Nearsightedness
(myopia) is a vision disorder that causes far objects to appear blurred but near
objects are seen clearly. Corrective eyeglasses with concave (inwardly curved)
lenses compensate for the refraction error by moving the image of a distant object
backward onto the retina Farsightedness (hyperopia) is a condition that allows
far objects to be seen clearly but presents difficulty with near vision. Corrective
eyeglasses with convex (outwardly curved) lenses compensate for the refraction
errors by moving the image of a distant object forward onto the retina. Astigmatism
is a vision disorder caused by a non-uniform curvature in the refractive surfaces
of the eye. Light rays do not all come to a single focal point on the retina,
some focus on the retina while others focus in front or behind it. This condition
can occur in conjunction with nearsightedness or farsightedness. A special cylindrical
lens is placed in the eyeglasses to correct the condition. Presbyopia is a condition
that exists when the natural crystalline lens of the eye loses some of its ability
to change shape in order to focus on near objects. Typically, people moving beyond
the age of 40 eventually develop presbyopia, which is indicated by a need for
reading or bifocal eyeglasses. Corrective eyeglasses with convex lenses compensate
for these refractive errors.
Nowadays,
eyeglasses have developed into fashion accessories that can completely
transform your image. No more are the days when eyeglasses were worn solely to
correct one's vision. While focusing on the aspects of Fashion, Fit and Function,
consumers can assertively shop for eyeglasses that will surely fulfill all of
their needs. It's as easy as deciding the look you want, defining the shape of
your face and your coloring and choosing the eyeglass materials and frame that best complements
your hair, eyes and skin tones.
So, "What
About Eyeglasses"?
The answer is easy at EyeglassDirect.com
