TYPES OF LENSES Review the various lens designs and choose what fits your lifestyle.
Single Vision
Single vision lenses function as all purpose glasses
for persons who have normal accommodations. Persons who normally wear
bifocals or trifocals
can use single vision for distance or near (reading) lenses. Single
vision lenses can also function as occupational glasses for certain
types of work. Single vision lenses are available in all lens materials.
Bifocals (Flat Top)
A flat top bifocal is a correction for distance
and near vision in one pair of glasses. Flat Top 28 is the most popular
bifocal form. It is also available with the bifocal portion made in a
variety of widths (Flat top 35 and Executive Bifocals) to help with various
close-up occupations. Flat tops are made in all lens material types.
Executive Style Bifocals
Sometimes used for those who need a wide field of
vision for near work (accountants, for example), Executive Style Bifocals
have a distinctive appearance and are thicker because of their design.
They are generally only available in hard resin and polycarbonate.
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 blurred 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
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 becoming the lens of choice
for bifocal and trifocal wearers.
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's eliminate the "bulgy" appearance
of strong plus lenses (far-sighted corrections) and greatly enhance the
appearance of finished eyewear. Persons 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.
Sports Glasses
All sorts of special lens designs are available
for the special needs of sports enthusiasts. Poly carbonate 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 outdoor activities.
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LENS MATERIALS
Your first decision involves the material in which you
want your new lenses made. When appearance and comfort are important,
you may want lenses made in poly carbonate or high index. If active sports
or work play a role in your lifestyle, you'll want to order poly carbonate
Or, you may want lenses that automatically darken in sunlight. The following
information will help you make your choice.
CR39 - Plastic
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.
High Index
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.
Transitions
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
a moderate shade of grey or brown.
Polycarbonate
Poly carbonate lenses are the most impact resistant
lenses available and are always the lens of choice for young people and
active patients. Poly carbonate lenses are high index and 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.
Varilux™
Varilux lenses
enable your eyes to make a smooth, gradual transition when you change
your focus from near to intermediate to far vision. Unlike bifocal lenses,
Varilux lenses eliminate the line that creates an abrupt, annoying vision
change from near to far vision. The added comfort of Varilux is achieved
with an increased field of vision. This larger vision field reduces unnecessary
head movements both vertically and horizontally, which means you can
assume a more natural, comfortable posture when viewing objects at close
and intermediate ranges.
Glass
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.
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LENS
COATINGS & TREATMENT Tint
All lens materials except glass can be tinted
in any color desired. Shades of any color ranges from 1 to 4 with
3 (ie. a grey #3) being the most common sunglass shade ordered.
Solid and gradient tints are available.
UV
Protection
It is generally accepted that the ultraviolet
rays in sunlight pose potential harm to eyes. Specific treatment
is available for plastic lenses that completely blocks hazardous
UV light. Lenses like poly carbonate and high index include built-in
UV protection at no extra cost.
Anti-Reflective
Coating
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.
Scratch
Protection
Light weight plastic lenses can be more easily scratched than glass. Eye Deal
Eyewear offers a one time replacement warranty against scratches during the
first year.
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HOW SHOULD I LOOK AFTER MY EYEGLASSES?
• DO NOT place them
face down.
• DO NOT put them on and take them off with one hand as this can stretch
the joints.
• DO NOT clean plastic lenses with tissues.
• DO keep them in a case when not worn.
• DO clean them with a soft cloth and suitable cleaning fluid or a drop of
warm water and detergent.
• DO come back and have your frame adjusted if required - There is no charge
for this.
• DO remember that if you are dependant on your eyeglasses for driving or
for your work you should
 consider a spare pair in case of loss or breakage.
Many people don't think about this until it is too late.
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STANDARD LENS POWERS RANGE
Sphere Powers: +/-6.00 diopters in .25 increments
Cylinder Powers:
-3.00 diopter in .25 increments
Bifocal Style:
Flat top-28mm segments with adds up to +3.00
For non-standard range prescriptions, additional fees will apply and are noted
before final purchase.
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