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Spectacle lenses
come in large number of different
materials, designs, tints and
coatings. The sheer number of
choices can be bewildering. We,
at Richard Suckling Optometrists,
have had years of experience to
help you make the lens decision
which is best for you.
Today, lenses can be made much
thinner and lighter than ever
before. High index materials can
dramatically reduce edge thickness
for myopes (shortsighted people)
and for people with higher prescriptions.
Flatter aspheric lens designs
can reduce the bulbous appearance
of some hyperopic (longsighted)
people’s prescriptions.
Lens coatings and tints have improved
too, in recent years. Slippery
multicoated lenses, which are
much easier to clean, are now
available. Multicoated coated
lenses reduce annoying reflections,
look nearly invisible and have
a nicer, more fashionable appearance.
Photochromic lenses, which darken
and lighten in the sun, now change
much faster than they ever used
to.
High index lenses
are spectacle lenses made from
materials that bend light more
than standard materials. The higher
the refractive index of a lens,
the greater its ability to bend
light. High index lenses come
in a variety of refractive indexes,
some varieties bending the light
much more than others. High index
lenses can be made much thinner
than other lenses. The higher
the refractive index, the thinner
the lenses can be for a particular
lens power.
High index lenses are not only
thinner than standard lenses but
are often lighter and stronger.
If you have a higher-powered spectacle
prescription, high index lenses
along with a multicoat should
be your first choice.
However, it pays to remember that
although high index lenses have
many benefits not all high index
lenses are created equal. For
instance, polycarbonate, a medium
index plastic material sometimes
causes colour fringing which degrades
the image.
Because there are many varieties
of high index lenses it pays to
get advice about which varieties
will be best suited to your particular
prescription requirements. Our
job is to help you make the right
choice. We even have a computer
programme to help us. It calculates
just how thick any variety of
high index lens will be in the
frame that you have selected.
Today’s
spectacle lenses are usually made
from plastic that is then coated
with a scratch-resistant coating
to make it durable and long-lasting.
There are also special extra hard-coated
plastic lenses suitable for children.
Some of these scratch-resistant
coatings also incorporate a UV
filter that filters out nearly
all of the sunlight’s harmful
rays.
Spectacles made from glass, although
still available, are really a
thing of the past because of their
poor safety record and their weight.
Glass lenses are not usually coated.
Multicoats are special coatings
layered one on top of the other
to eliminate reflections and increase
the amount of light transmission
through the lens. Multicoated
lenses effectively eliminate reflections
making driving at night and viewing
computer screens more comfortable.
They also have a much nicer and
more fashionable appearance. Multicoated
lenses greatly reduce the edge
power rings effect of lenses with
thicker edges. Also, multicoats
help to reduce the colour fringing
(chromatic aberration) seen with
some high index lenses. Multicoated
lenses are recommended for stronger
prescriptions and for flatter
aspheric designed lenses.
Progressives
(sometimes called multifocals)
and bifocals are lenses designed
for people over 40 who have presbyopia.
The number one reason people get
these lenses is convenience, so
that they don’t have to
take their spectacles on and off
all day.
Bifocals are lenses with two focal
lengths, one designed for distance
and the other designed for near.
They give good distance vision
in the top half of the lens and
good reading vision in the lower
half. However, there is a bit
of a no-mans land between these
two visions often making working
on a computer, playing music or
playing a sport like golf, difficult.
Seeing prices on the supermarket
shelf may be difficult and even
walking on uneven ground can be
(because you can’t see the
bumps and hollows in the ground).
Progressives (multifocals) are
now much more popular than bifocals
and with the newer better designs
this trend will continue. Progressives
do not have a line between the
top half and the bottom half of
the lens. They progress smoothly
in power increments through a
middle part of the lens that can
be used for intermediate vision
tasks like looking at the computer
or at prices on the supermarket
shelf. However, progressive lenses
have weaknesses. Generally speaking,
the reading portion of progressive
lenses is narrower than that of
bifocal lenses and they can take
a bit of getting used to wearing,
often 2 or 3 weeks. Some people
find that progressive lenses give
them problems with motion sickness.
Progressive lenses also come in
a large number of different designs.
Some designs are more suited for
reading while others are more
suited for walking. Still other
designs are for shallow spectacle
frames and others, like occupational
progressives, are for those working
on computers. It is important
to make an informed choice about
which lens is best for you.
All our progressive and bifocal
lenses are of the highest quality
material and designs. They are
made by companies like Hoya, Nikon,
Essilor, Sola, Rodenstock and
Zeiss.
Photochromic
lenses are variable tinting lenses
that darken when the sunlight
shines on them and lighten to
become clear when out of the direct
sunlight. Photochomic lenses can
be made in plastic or in glass.
Sometimes people refer to photochromic
lenses as transition lenses because
one brand of plastic photochromic
lenses is called ‘Transitions’.
Photochromic lenses are a wonderful
choice for those people who are
sensitive to sunlight, for those
people who are migraine prone
and for those people who spend
a good part of their day outside.
Outside, progressive lenses act
like sunglasses while inside they
are basically clear. Although
progressive lenses darken in the
car, they do not darken as much
as one would expect because they
are out of direct sunlight, shielded
by the windscreen.
Tired of your
sunglass fit over or clip-ons?
Separate prescription sunglasses
might be a good option for you.
The most straightforward prescription
sunglasses have lenses with a
permanent tint . This tint has
a special dye that reduces that
the visible light down by 70-80%
and cuts out all harmful UV light.
The most popular sunglasses lens
tints are grey, green and brown.
Sunglasses with grey lenses and
with grey plus a touch of green
give the most natural colour while
brown lenses give the most cheerful
appearance. However, we can provide
a wide variety of colours and
are able to match almost any colour
you might require.
Polarised lenses are a great choice
for driving and for fisherman.
These cut out reflect light so
it is possible to see in to water
because the lenses cut out all
the reflected light off the surface.
Similarly, glare reflected off
the road while driving is also
eliminated. It is now possible
to get a polarising, photochromic,
sunglass lens, which varies the
amount of tinting depending how
bright the sun is.
We will use a nice fashion sunglass
frame modifying the spectacles
prescription to allow for the
wrap of the sunglass frame.
Adidas and Ruby Project have sunglass
models that allow standard clear
lenses to be clicked in behind
the sunglass lens. This means
you can get full wrap around sunglasses
for cycling and skiing.
Did you know
that special tints are available
for shooting and skiing?
Did you know that you can have
your ordinary spectacle lenses
tinted and turned into sunglasses?
Come in and talk to us about any
special requirement lens tints
you might want.
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