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Progressive
lenses or "blended" lenses are designed to give clear
vision for viewing objects at any distance. As you reach
your mid forties you will notice that your reading
vision isn't as clear as it used to be. For those who
have never worn glasses and don't need a prescription to
see clearly at distance simple over-the-counter
"readers" may work fine. Near-sighted (myopic) people
may be able to just take their distance glasses off and
see fine up close. Far-sighted (hyperopic) folks need
even more help up close and they seem to need bifocal or
progressive lenses at an earlier age than those who have
perfect distance vision or those who are
near-sighted!
Prior to
the invention of progressive lenses people wore bifocals
or trifocals (the lenses with lines in them)when they
reached the "magic" age. These lenses work fine for most
tasks except computer work.
Computer screens have a working distance of about 26
inches on average. This is a little too far for the
bottom part of a bifocal and too close for the top
distance portion of the lens. Fortunately, progressive
lenses have an area in them just right for the computer
working distance.
It takes a
bit of adjustment to become comfortable with using
progressive lenses but most people do adapt with time.
However, I have found that people who have excellent
near or distance vision without correction have a
more difficult time adapting to these lenses. Also, if a
person has never worn spectacles before at all, they may
also have a more challenging task in
adapting.
I looked in
the catalog listing all the brands and models of
progressive lenses and there was 480 different lens
models! Some of them came in 5 different lens materials
so the total number of choices is amazing. Some models
are easier for first time users to adapt to. Some have a
wider intermediate zone which makes them even better for
computer use. Some have real short, fast blends which
work in the fashion frames that have small vertical lens
dimensions. Some have clearer, broader peripheral
vision. The goal is to pick the right lens for what the
visual requirements are for the person and the size of
the frame they choose. This takes a bit of practice for
the practitioner to learn as does learning how to adjust
the frame to fit comfortably and properly.
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Progressive Lenses
