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Software Vault: The Gold Collection
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Software Vault - The Gold Collection (American Databankers) (1993).ISO
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GLASSES.TXT
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1993-05-30
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Eye Glasses In The Computer World
by Jim Fulton, Orange Coast IBM PCUG
Although not an Optometrist, but a user with 30 years of optical
engineering experience, I would like to address Stephen Burnside's
quest for help with eyeglasses. During the 1980s, we have
increased the demands on our eyeglasses (and our Optometrists) more
than at any time since Ben Franklin introduced bifocals to solve an
earlier problem, a broader ability of the population to read. Until
recently (except for pilots and a few others) the population sought
glasses which allowed them to read books in hand--good focus at
12-14 inches --and good distant vision to see stars and ships and
shoot ducks.
More recently, our needs have frequently been to read over a wider
range of distances, typically from 12 to 30 inches or more. In my
case; I am big and have long arms, work on large drawings and need
to read a blackboard from a desk. And--I want to do it all over a
field of view which is wider vertically than the range provided by
an airline pilot's trifocals.
To meet my needs I work closely with, and carefully instruct, my
Optometrist on what I want him to provide me in the way of bifocals:
1. I tell him I want to read optimally at 16 inches. This typically
allows me to read print and video display terminals (VDTs) over a
range from about 8 inches to 28 inches thru the reading portion of my
glasses.
2. I tell him I want to read blackboards, projection TVs and
building directories at 5 feet (60 inches). This results in my being
able to read well from less than 28 inches (VDT distance) to about
12 feet thru the upper portion of my glasses.
3. I request the "executive style" lens which provides a wide field
of view for the "reading" portion of the lens. The results of these
instructions are: My ability to read effortlessly over a range of
8 inches to about 12 feet and a horizontal field of view of about 30
degrees. The focus is equally good through either section of the
lens at about 24 inches.
I can't read the 20:20 line on a standard eye chart at 20 feet
(not a big loss) and stars, as well as, other point objects at
great distance are in poor focus at night. While "processing these
words," my pencil draft was at 16 inches and low, my VDT was at 30
inches and high, and the hockey game was on at 84 inches and high
in my field of view--all in good focus simultaneously, thank you.
Even though I touch type, I should point out the keyboard at about
16 inches was also in good focus.
As a point of information, the Motor Vehicle Department (DMV) asked
me to take a quick eye test at about 10 feet on my last visit. The
glasses and I worked fine at this distance in daylight. There is a
problem related to item 2 previous; I cannot see well in a dimly lit
auditorium at distances of over 20 feet with these glasses.
Specifically, I cannot see the graphics projected at the General
Meeting or theatrical presentations. For these situations, I use my
first conventionally prescribed set of bifocals.