Varifocals
Varifocals are for those individuals who require
separate prescriptions for different distances eg those who need one
power for watching TV and a different strength for reading.
The lenses have a gradual change in power from the top to the bottom,
allowing you to see clearly at all distances with just one pair of
spectacles. The lenses look just like
normal ones – there are no visible dividing lines.
How They Work
The lenses are positioned so that when you look straight ahead, you
automatically look through the distance portion of the lens. To read,
the gaze is lowered as normal, and your eyes will then automatically
look through the reading zone. To look at something at arms length,
you simply raise or lower your head slightly until the object comes
into focus. After a while the process of finding the correct part
of the lens for each different viewing distance becomes automatic
and you don’t have to think about it all.
Different Varifocal Designs
Varifocals come in different designs and the variations between them
can be quite dramatic. The dissimilarities are related to factors
such as the size of the different areas allocated for reading, distance
and intermediate as well as the amount of distortion in the lens.
Some have wider reading areas than others.
Some have bigger distance portions than others.
Some have wider corridors - all varifocals have a central ‘corridor’
over which the power change occurs. On either side of this zone,
the lens surface is not perfect and suffers from distortion. The wider
the corridor the bigger the area of vision.
Some have more pronounced distortion - things are more out of focus
when looking through the non-central parts of the lens.
Some are compacted (the distance and reading portions are closer together)
so that they can be put into smaller frames.
Getting Used to Them
Varifocals do require some initial adaptation, but on the whole the
success rate is very high at over 90%. Better success is achieved
with the newest designs that have wider corridors and less edge distortion.
A small number of individuals however just don’t find them suitable.
That’s why all the varifocals we supply come with a 30day exchange
warranty. If someone really doesn’t get on with them, they will
be exchanged for single vision alternatives. The initial cost of the
varifocal lenses will be credited against the cost of the replacement
glasses and usually there will be nothing further to pay.
Varifocals & Small Frames
It used to be the case that varifocal lenses could only be put into
large frames however newer designs have been launched that are suitable
for small, shallow frames. You’ll be surprised at how small
you can go. |
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