Even the best displays quickly make
your eyes tired, because...
a. They're grainy
A good resolution is about 100 dots
per inch - that's a third of the sharpness of newsprint.
b. They flicker
Most people have to run a CRT display
at high refresh - 75Hz or more - to get decent results. LCD screens are
better, but reading off screen is always slower and more tiring than
reading off paper. Also, some people are particularly sensitive to
screen flicker.
c. Staring at screens is bad for your
eyes
Looking at a screen from the same
distance for long periods leaves our eyes weak, dry and sore.
(To protect your vision, experts
recommend taking a short break from the computer every 20 minutes, walk
around. Focussing at different distances strengthens the eye muscles.)
How users cope
Computer users quickly start learning
time-saving shortcuts to try to make life easier on the eyes. In order
to reduce the time we spend looking at the screen, we:
- are very impatient
- make quick decisions
- scan pages, instead of reading
Good design appreciates these
considerations, and deliberately helps users have a quicker, less
tiring experience.
