<snipped>
Thanks for your insighted reply, Robert.
If anything CRTs can be worse for the eyes. However, you need to
understand some facts about the human eye/brain connection to put this
into context.
I though already something like that.
Especially considering that we have TL-lights everywhere in the house
(energy saving) which cause extra flickering.
Staring at any small screen -TV or computer- for extended periods of time
is "hard" on the eyes. That is because the eyes do not move in the head
and the muscles get tired from holding the eyes in a fixed position. No
permanent damage but headaches could result.
This is a problem and a dilemna for me.
Refusing my child access to the computer after "x" hours of use is not so
easy.
If she would not be looking at the computer, she would be watching one or
another TV-program (shoot, kill, rape, war, etc...)
For the moment, she uses the computer only to learn.
No games.
And only a few hours after homework (2 hrs at the most).
CRTs flicker at the vertical sync rate. If this rate is low 60-70 Hz, the
brain will detect the flicker which causes fatigue and possibly headaches.
Detection of flicker decreases at higher vertical sync and good monitors
can work at 85Hz or higher rates. This reduces or eliminates the problem.
LCD monitors do not have this problem even at 60Hz vertical because they
do not flicker.
So, LCD screen is a better option.
Use of a computer for extended periods of time without at least getting
up and stretching is not a good idea regardless of the monitor.
Rapidly changing patterns can lead to epileptic seizures in susceptible
individuals. There can be damage to legs (clot formation) caused by
impaired blood flow similar to that reported in long airplane flights
where you are confined to your seat. There can be damage to the spine if
the chair used does not give proper back support.
Sheeeeeeeeeeexz,
I wasn't aware of all these causes of using a computer.
I knew the law in my country (Belgium) which is very severe for work at a
computer.
At my work as a CAD drawer, I was required to leave the computer every 50
minutes and walk for 10 minutes.
My seat was "energomical" designed to reduce the symptomes of working at a
computer maximal.
But I never saw such a report as yours.
I guess I will have to apply the Belgian Law to the computer use by my
daughter (4 1/2 years).
Does any of the above matter to you or your child? Only you can determine
how your computer is used, the susceptibility of the user to one of these
problems, and whether the true difference (flicker) merits the expense of
a new monitor or just a change in the screen refresh rate.
You have surely lead my decision in the right way and first thing tomorrow
will be to get lost of the old CRT monitor and look for a bigger (19 inch)
LCD screen.
The 19 inch LG, ACER and TCL screens are the better ones as compared in a
local magazine.
These monitors are sold at the local IT-Store for about $250.
Besides the choice of the monitor, I will need to put restrictions on the
computer use and the TV use.
Raughly the same as the Belgian Law on computer use at work.
Reading your response, I wonder how much damadge the use of a computer is
doing to the people at the local Internet stores. I live in Thailand, and
there are many "Internet Games" stores where children from 7 years up are
playing games online like "Counter Strike" with the sound at full power for
many hours without a rest. .
Thanks again for your reply, Robert.
Regards,
Melissa