Re: Screen Fatigue

["Virginia L. Krenn" <asdxvlk -at- OKWAY -dot- OKSTATE -dot- EDU>]

      I have noticed that on my way home after an extra long day in front of
      the tube, that I have double vision on the traffic lights. This doesn't
      happen any other time and doesn't worry me as much as it did when I first
      started experiencing it.

______________________________ Reply Separator _________________________________
Author:  Rick Lippincott <RJLIPPINCOTT -at- delphi -dot- com> at SMT

All the discussion about screen fatigue vs. printed page eye fatigue seems
to focus on resolution of the image, dpi, etc.

I always thought there was another reason for screen fatigue, and it hasn't
been mentioned at all.

Most of us are working in offices with fluorescent lights, running on AC
current.  In the US, that means the lights are actually flashing at 60hz,
(too fast for your eye to detect, but flashing)  The monitor on the computer
is also running off the AC current, and (interlaced or non-interlaced) it's
also flashing at (US) 60hz. Even if the power source for both is in phase,
it's impossible for the flashes to reach your eye in phase.  (You'd have to
have the distances between light, monitor, and eye set to a ratio accurate
within one wavelength of light, and -I- can't hold my head that still.)

In effect, we're sitting at our desks with two out-of-synch strobe lights
flashing in our faces.  It would seem to me that this would cause fatigue.

Has this been explored?  Explored and disproven?

Should I go get some coffee now?

Rick Lippincott
rjlippincott -at- delphi -dot- com