Here is a small chunk from the ‘The Jewwlry Workshop Safety
Report’ book I am working on. You should note this is in draft
form only and will be added to in the book. the additions have to
do with the difference between magnification and focus, and how
some people may see well close up as they age.
I spoke with several Doctors of Optomettry in Calgary; Dr. Bruce
Redmond, Dr. Allen Jones and Dr. Craig Meckelborg asking them
about eye issues and whetehr the use of magnification had any
particular dangers to it.
Because jewelry work is often very exacting in its details
goldsmiths tend to use magnification at times, often to check
their work. Engravers and stone setters in particular use
magnification freqently. Some goldsmiths will use an optivisor,
some a lens that attaches to glasses or fits into an eye socket,
some work under a binocular microscope.Dr. Jones noted that if
magnification is properly arranged then the eye’s focus is set
at infinity, much as if one were looking into the distance. Dr,
Redmond commented that using one eye excessively may cause strain
and as with a monocular miscroscope it is important to learn to
keep both eyes open when using magnification.
With age the focussing lens of the eye gradually loses
flexibility resulting in blurred vision and loss of the ability
to focus on close things. This condition is called presbyopia. It
can occur as young as thirty and usually occurs in the eraly
forties. By the time one is 55 almost everybody has the condition
and needs reading glasses or bifocals to work up close. Symptoms
of presbyopia include a tendency to hold reading material at
arm’s length; difficulty reading in dimly lit environments; tired
eyes or headaches after concentrating on close work; and blurred
vision at the normal reading distance.
All the physicians we spoke with felt there were no particular
safety issues associated with using magnification. Dr. Meckelborg
noted that when using magnification such as a microscope (as is
used in gemmology, and certain engraving and stonesetting
procedures) there is some possibility of the eye drying out and
becoming sore from this. On average people blink (and moisten)
their eyes about 12 times a minute. When concentrating hard
however the blink rate slows down to as low as 4-5 blinks a
minute, increasing the evaporation rate and dryness ensues. So,
if you are concentrating hard, or using a microscope for longer
periods of time you should try and remember to blink.
Some stone setters have glasses made for them that magnify 3, 4
or even 7 times. The wide field of vision is very pleasant.
A number of people use ‘drug store’ reading glasses for minor
magnification in the studio. They seem to like them because they
are inexpensive (and thus easy to replace if scratched). One can
purchase side protectors which clip onto ordinary glasses which
help prevent things flying into the eyes if used in the workshop.
These kinds of glasses are also made from plastic (and thus may
be less likely to shatter).
One can apparently obtain such reading glasses which are
darkened up to a #5 shade strength useful for brazing. (Buddy
Holmes, Artmetal list, 1/11/97, 'Re: Eye Safety Issues (Again))
Dr. Meckelborg suggested that an adult aged 40 or so should have
their eyes tested every two years or so as a matter of course. He
also pointed our a subtle distinction that is worth noting, that
focusing is not the same thing as magnification.
Charles Lewton-Brain/Brain Press
Box 1624, Ste M, Calgary, Alberta, T2P 2L7, Canada
Tel: 403-263-3955 Fax: 403-283-9053 Email: @Charles_Lewton-Brain
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