Transitions
lenses are today's clearest, darkest and
fastest-activating photochromic lenses
changing from light to dark when going
indoors to outdoors.
Are
your eyes tired? Crizal premium anti-reflective
lenses reduce the glare that causes eyestrain
and they're two-sided scratch resistant,
so you can see as clearly as your eyes
were meant to.
The
perfect compliment to your active lifestyle,
Airwear polycarbonate lenses are the most
scratch-resistant, durable lenses providing
100% UV protection.
Experiencing
a harder time reading menus at restaurants?
Varilux, the #1 recommended progressive
eyeglass lens, helps to correct presbyopia
or over forty eyesight, enabling you to
see
near, far and everything in-between.
PRIO not only provides
you with the information and resources
needed to prevent computer vision syndrome
(CVS), PRIO has numerous products designed
specifically to diagnose and treat this
growing problem.
In 1987, PRIO designed
the only class 1 medical device designed
to diagnose and treat CVS. However,
as awareness of the problem has grown,
so has PRIO. Today PRIO offers specialized
vision testers for adults and kids,
computer lenses and PRIO frames to create
a complete solution for computer vision
syndrome.
TRIVEX
is the world's first tri-performance lens
material; meaning it offers a triple combination
of features never before found in a single
material. Superior Optics.
Impact Resistance. Ultra light Weight.
This breakthrough in technology is specifically
designed to deliver the most comprehensive
performance of
any lens material, anywhere.
Eyeglasses can correct
numerous refraction problems.
The most common are nearsightedness, farsightedness, astigmatism
and presbyopia.
Concave and convex lenses compensate for defects in
the eye, bending
light rays to place them precisely on the retina and correcting
vision.
A concave
lens is thinner in the center and thicker on the edges. It bends
light so that it converges further back in the eye, reaching
the retina and correcting nearsightedness. A convex lens is
thicker in the center and thinner on the edges, opposite from
a concave lens. It bends light to converge further forward in
the eye, landing on the retina and correcting farsightedness.
Concave and convex lenses can be used separately and in combination
to correct a variety of vision problems.
Lens varieties
include:
Single-vision
lenses - Single-vision lenses have the same focusing
power over the surface of the whole lens. They may be prescribed
for distance, near or reading-only vision.
Bifocals
- Bifocals meet dual vision needs. The lenses are sectioned
into two or three parts that correct vision at different
distances. The upper part generally has the power you need
to see in the distance (or has no correction), while the
bottom portion has the strength you need to read. The line
between the sections of the lens bothers some people, as
objects appear to jump when eyes cross the line.
Bifocals provide near vision correction, and may
also provide
distance correction in the upper portion.
Trifocals
- Trifocals meet vision needs at three distances. Similar
to bifocals on the top and bottom, there is a middle section
designed for vision just beyond reading distance.
Trifocals correct vision at three times the distances.
Progressives
- These are similar to bifocals and trifocals but the variance
in the lenses is more gradual, correcting vision at every
distance and eliminating visible lines.
Progressive lenses correct at multiple distances
and provide a
gradual transition instead of visible lines and abrupt
shifts.
Some distortion may be noticed in the lower corners.
Choosing Lens Materials
Lenses
are made from several materials. There are a great many lens
formulas and coatings with different performance characteristics.
Glass
- Original material used for glasses, these lenses are made
mainly of sand (silicon dioxide) plus various elements (such
as titanium dioxide for thinness). Glass lenses are long
lasting and naturally scratch-resistant. They are heavy
and breakable but can be treated for shock resistance.
Standard
plastic - Developed in the 1960s, plastic lenses are
made of a hard resin that is light and impact resistant.
It is thick and easily scratched unless treated with a protective
coating.
Mid-index
plastic - First used in the early 1990s, higher index
refraction means this material reduces lens thickness without
compromising optical performance. It is recommended for
light to moderate prescriptions. A protective treatment
can reduce scratches.
High-index
plastic - The third wave of plastic materials provides
an even higher index of refraction. It is ideal for those
with moderate to severe correction needs because higher
power prescriptions can be made lighter and thinner. A protective
treatment can reduce scratches.
Polycarbonate
- The newest lens material is an acrylic-like resin that
is used for airplane windshields. It is the thinnest, lightest
and most impact-resistance of all lens materials, and comes
with a scratch resistant coating. Polycarbonates are also
inherently good at filtering UV rays.
Selecting Lens Treatments
All of
these materials can be treated to better protect your eyes,
improve your vision, increase the durability of your lenses,
and enhance appearance. Scratch-resistant coatings, ultraviolet
light blockers, anti-reflectives, tints and edge treatments
can be combined to meet your individual needs.
Scratch-resistant
coatings - Plastics and polycarbonates are usually treated
with anti-scratch varnish. The coating can be used on the
front, back, or both sides of the lens.
Ultraviolet
light blockers - While some materials are better than
others at filtering damaging ultraviolet light, the only
way to get 100 percent protection is with specific UV treatments.
Anti-reflective
- Anti-reflective treatments (AR) have two purposes: eliminate
the glare others see when looking at you, and eliminate
reflections and glare that you experience when looking through
your lenses. Together, these effects improve your appearance,
comfort and safety. Users typically notice less glare from
fluorescent lighting, computer screens and car lights. Contrast
and detail are improved, reducing eye strain and headaches.
AR-coated lenses used to attract more dust and show dirt
and smudges more easily than non-AR coated lenses. But today,
many AR treatments include a final coating that better repels
dust and dirt and makes lenses easier to clean.
All-in-ones
- The newest option is an "all in one" coating, combining
the advantages of scratch-resistance, anti-reflection, and
smudge resistance to offer the ultimate lens treatment.
Tints
- Lenses can be tinted or colored for a variety of reasons.
Most often tints are intended to filter out some light,
as in sunglasses. The right tint for you will depend upon
your vision needs and your sensitivity to light.
Clear
- Lenses with no tint allow the maximum amount of visible
light to reach the eye.
Color
- Lenses are available in virtually every color imaginable.
The color chosen can be for sun protection, personal
style and to enhance sight. Sun protection colors are
usually grey or brown. Polarized lenses eliminate the
most reflective glare and are recommended for driving
and around water.
Gradient
- Gradient lenses have a darker tint on the top and
gradually get lighter toward the bottom of the lens.
They are usually chosen for appearance and sun protection.
Photochromic
- These lenses are clear when indoors and dark when
in the sun. The tint is activated in only a few moments.
They are convenient and comfortable, minimizing the
need for both clear and sunglasses.
Edge treatment
- Lenses are cut to fit the shape of the frame. This leaves
a frosted, rough edge. This is especially noticeable with
higher prescriptions that result in thicker lenses. The
edges can be polished to provide a finished look, or left
with the frosted look.
