Defining the Various
Eyeglass Lens Options Part I
Types & Differences of Each Eyeglass Lens Options
When it comes to eyeglass lenses, there is much more than
meets the eye. If you think that eyeglass lenses have a prescription
and are shaped to fit within your chosen eyeglass frame, you'd
be since it is how being offered for years. And while eyeglasses
are great at correcting a multitude of vision problems, they
offer even more benefits.
Of course, you need to bear the cost of these new and improved
benefits, and the more you choose, the more it is going to
cost. How to determine which eyeglass lenses are right for
you?
Anti-reflective eyeglass lenses are essentially coated with
metal oxides which improve vision by reducing glare and reflection.
Reflections on the surface of an eyeglass lens can potentially
lead to ghosting and eye strain. Anti-reflective coatings
remove these problems and those which are caused by such things
as oncoming headlights and fluorescent lighting reflecting
off computer screens, two big sources of strain. These coatings
also make glasses look better as the surface won't have that
obvious mirror effect.
High index eyeglass lenses abolish the need for that legendary
'soda bottle look'. The rule of thumb has always been the
stronger the eyeglass prescription, the thicker the eyeglass
lens in order to accommodate the right amount of light bending.
High index lenses changed that and their development has enabled
eyeglass frame manufacturers to start creating extremely thin
or rimless frames.
High index lenses which are made out of plastic are very
light since there will be less material used in the construction
of the lenses. These lenses can also be made from glass as
well, but due to the fact that glass is heavier, the end result
won't be a lighter feeling lens. There is a range of high
index lenses and understanding higher vs. lower index is a
rather tough, so you should let your eye doctor explain the
differences. Generally, higher indexes cost more and should
be thinner. These eyeglass lenses also benefit from the addition
of an anti-reflective coating which blocks less light.
Photochromatic lenses change from regular clear lenses into
dark-colored lenses, which is similar to that on sunglasses,
when they are exposed to sunlight. The convenience of having
'2 pair of eyeglasses in 1' is less costly. Transitions lenses
are the most familiar of this type of lens and they are available
in almost every prescription and refractive index.
They also offer full ultraviolet protection. The secret behind
the color changing capability is silver halide which is usually
mixed right into the lens when it's being created. In the
early days, thicker parts of the lens resulted in darker areas,
however, this condition has been entirely eliminated with
the introduction of polycarbonate and high-index lenses. Besides
Transitions, many other companies offer some variation of
the photochromatic lens. Corning, the original developer,
has a couple of styles such as Thin & Dark and SunSensors,
and also the originals, PhotoGray and PhotoBrown.
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