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Nigel. Mary Meagher wrote in the last issue ("Lookout")
that we pilots should not wear Varifocal lenses. I thought it might be
useful to add my own experience here, as I don't think the answer is as
simple as that.
I started wearing Varifocals many years ago - not because of macho airline
pilots!. The choice at the time was bifocals or varifocals. I just could
not get away with bifocals - first of all they didn't help the mid-range
(looking at computer screens) and secondly they just about ripped your
eyeballs out when you went across the transition layer. At the time I
was recommended to take glass varifocal lenses mainly because one eye
is much worse than the other on long range (short-sighted) and the relevant
plastic lens would have been twice as thick. I had no problems with peripheral
vision using these glass lenses.
A few years ago I had a prescription change and the optician ordered plastic
lenses ("because they are much lighter and really very good these
days...") I stressed the requirement for good peripheral vision and
was assured there would be no problem. Unfortunately this advice was incorrect
- the new plastic lenses caused severe distortion at the periphery and
were just no good. They did try another different plastic lens manufacturer,
they were just as bad, so I ended up with glass again.
Just last month I had another eye test and although the change was small
I ordered new glass lenses (you can do a lot of hours for the price of
varifocal lenses!). The new glasses were delivered - with plastic lenses
- and with the same unacceptable peripheral distortion. They were immediately
handed back for a full refund, and I am now seeking a new optician who
can deliver what the customer asks for.
There are some new plastic lenses which cost even more (you're looking
at £450 for a pair of glasses, times two to get the requisite spare
pair) - if anyone has tried these it would be interesting to hear the
results. Meanwhile I'll stick to glass.
Peter Short.
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