The material and type of lens you chose, should depend on your prescription, frame style preferred, frame type, lifestyle activities, facial measurements, and most importantly, the recommendation of your eyecare professional.
Hard Resin
(plastic or CR-39)
Conventional hard resin lenses are half the weight of glass lenses
and can be tinted to almost any color and density. Hard resin lenses are
more easily scratched than glass but can have an optional scratch
protection applied. More impact resistant than glass, hard resin lenses do
not require heat treating.
Lighter, Thinner
Lenses
Modern technology has created lenses
that bend light differently so that stronger corrections are thinner than
when made in conventional materials. Such lenses are called "high index"
and stronger corrections are more attractive because they are slimmer.
Glass lenses are also available with the slimming advantages of High index
but are considerably heavier. High index plastic uses less material so
they are often lighter in weight. High index lenses absorb all harmful UV
light and can be tinted to any shade or color.
Lenses That Darken in the
Sun
These are lenses that darken as you go
from indoors to outdoors. They are available in both glass and lightweight
hard resin. They darken to shades of grey and brown. Ask for a
demonstration of photosensitive lenses.
Polycarbonate
Polycarbonate lenses are impact resistant lenses
and are the lens of choice for active
patients. Polycarbonate lenses are usually the
lightest, most comfortable lenses. They absorb all harmful UV light and
can be made with ultra thin edges because of their unique
strength.
Trivex
Trivex lenses are impact resistant lenses
and are a lightweight, durable mid-index lens material that is considered
an upgrade from its industry-standard CR-39 (plastic) and are the lens of
choice for active
patients. They absorb all harmful UV light and
can be made with thin edges because of their unique
strength.
Glass (Crown)
For years glass was
the only lens material available and glass still offers superior optics.
The most scratch-resistant material, the primary disadvantage of glass is
its weight, generally twice that of hard resin. Glass lenses are heat or
chemically treated to increase impact resistance.
LENS DESIGNS
Single Vision Lenses
Single vision lenses function as all purpose glasses for
people
who have normal accommodation. People who normally wear bifocals or
trifocals can use single vision for distance or near lenses. Single vision
lenses can also function as occupational glasses for certain types of
work. Single vision lenses are available in all lens materials.
Aspheric
Lenses
These new lenses provide special
visual and cosmetic benefits for stronger corrections and increase edge to
edge clarity. Flatter than conventional lenses, aspheric lenses eliminate the
"bulgy" appearance of strong plus lenses (far-sighted corrections) and
greatly enhance the appearance of finished eyewear. People with strong
nearsighted corrections also benefit from thinner, lighter weight glasses
when their lenses are aspheric. Because aspheric lenses are positioned
closer to the face, there is less eye magnification with farsighted
corrections and less "small eyes" look with nearsighted corrections.
Aspheric lenses are often made of high index materials for the ultimate in
thin lenses.
Flat Top
Bifocals
This is
an older style
bifocal form and has limited compatibility with many of today's lens
upgrades. The bifocal portion is made in a variety
of widths to help with various close-up occupations. Flat top bifocals are
made in every type of lens material.
Franklin Style Bifocals
Sometimes used for those who need a wide
field of vision for near work (accountants, for example), Franklin style
bifocals have a distinctive appearance and are thicker because of their
design. They are generally only available in glass, hard resin and
photochromic glass. They are being replaced by wide Flat Top
bifocals.
Trifocals
Trifocals come in a
variety of designs. Flat-top trifocals are the most widely used form. The
added segment provides clear vision at arm's length distance, the area
that is usually bluffed for bifocal wearers. Trifocals are available in
all lens materials.
Progressives (no line
bifocals)
These lenses provide all the
benefits of bifocals but add the feature of continuous clear vision at all
distances, including mid-range distance (arm's length). Progressives have
the cosmetic advantage of appearing to be single vision lenses so they
never reveal the user wears bifocals. Progressives are available in all
lens materials and also made in aspheric form. Because of their many
benefits, they are the lens of choice for bifocal and trifocal
wearers.
Occupational
Requirements
Many occupations impose
demanding visual requirements on those who wear bifocals or trifocals.
Special occupational designs are available to solve these special needs.
If the visual requirements of your job falls into this category, let us
know and we'll explain what will work best for your individual
needs.
Sports
Glasses
All sorts of special lens
designs are available for the special needs of sports enthusiasts.
Polycarbonate is usually the material of choice for active
sports.
Computer
Glasses
There are a variety of
options for those who use computers. These include special filters and
anti-reflection coatings.
Polarized Sun Lenses
These are the exciting sunglasses that eliminate reflected glare.
They are especially appropriate for drivers, fisherman, hunters and all
types of outdoors activities.
OPTIONAL LENS TREATMENTS
Scratch Protection Coating 
Light weight hard resin lenses can be more easily scratched than
glass lenses. Special coatings have been developed to help protect lenses
from normal scratching. The modest additional cost for such scratch
coating is usually a prudent investment.
UV
Protection
It is generally accepted that
the ultraviolet rays in sunlight pose potential harm to the eyes. Special
treatment is available for hard resin lenses that completely blocks
hazardous UV light. Lenses like polycarbonate and high index include
built-in UV protection at no extra cost.
Anti/Reflection
Coatings
Special anti-reflective
coatings are now available for spectacle lenses, much like those used for
fine camera lenses. These coatings are particularly effective for reducing
eye fatigue for computer operators and anyone driving at night. And, of
course, AR lenses enhance appearance by removing all distracting
reflections.
These are, by no means, the only lenses available. By telling us of any unusual work or leisure visual requirements, we can tailor exactly the right lenses for all your visual needs.