[AERNet] Fluorescent Lights

[Jim Allan]

Elaine,
can you post it to the APH website, or send to me and I will put on TSBVI.

One important issue with fluorescent lights is working with a computer crt
monitor (the big boxy things, not the thin LCD ones). Fluorescent lights
flicker 60 times a second (when the ballast goes bad the rate slows down and
it becomes visually noticeable). Your basic CRT monitor has a refresh rate
that many times is set to 60hz. When the light flicker and refresh rate of
the monitor are the same the monitor will seem to vibrate. This is very
fatiguing to the eyes.

So, if your monitor vibrates/flickers etc. or your eyes get tired quickly
when using a computer with a boxy CRT monitor under fluorescent lights, you
can...
1. switch to an LCD (thin monitor)
2. adjust the monitor's refresh rate (instructions at
http://kb.iu.edu/data/adjt.html)

Jim

> -----Original Message-----
> From: aernet-bounces at lists.aerbvi.org
> [mailto:aernet-bounces at lists.aerbvi.org]On Behalf Of APH LOUISVILLE
> Sent: Wednesday, May 02, 2007 10:15 AM
> To: presley at afb.net; aernet at lists.aerbvi.org
> Subject: Re: [AERNet] Fluorescent Lights
>
>
> Hi Ike,
>
> As you know, this is a favorite topic of mine.  Your buddies are half
> right.  The old lights flickered a lot and caused a lot of stress to
> persons using them.  But that is not the only issue for people with
> visual impairments.  The kind/color of light emitted from the tube, no
> matter what shape it is, is determined by the phosphors (or mineral
> dust) that coats the inside of the tube.  When buying tubes it is
> important to look at the code on the tube to determine what kind of
> light is emitted.  Every code should include a two digit number after
> the last slashmark in the code.  If that number is higher than 32, the
> tube will emit bluish light which is very demanding on the eyes and
> leads to photostress in many people who have eye problems.  Numbers of
> 32 and lower, emit light that is closer to the red end of the spectrum,
> and very easy on the eyes.
>
> I have a 30 page packet of information which covers most everything
> you'd want to know about lighting for persons with low vision.  Anyone
> who would like a copy can write to me at ekitchel at aph.org and I'll be
> happy to send it either by snail mail, or electronically.  Just please
> don't bog down the listserve with the requests.
>
> All the best,
>
> Elaine Kitchel
> Low Vision Project Leader
> American Printing House for the Blind
>
> >>> "Ike Presley" <presley at afb.net> 05/01/07 12:32PM >>>
> Hi All,
>
> I checked with some of my buddies in electrical engineering about the
> issue of fluorescent lights. It seems that the older style tube lights
> that are used in many buildings are the real culprit when it comes to
> causing physical discomfort for some people. The newer, compact
> fluorescent bulbs, that are spiral shaped do not have the same problem
> and these are the types of bulbs that are being recommended.
>
> If anyone knows anything different, please chime in.
> Ike
>
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