eye health , lcd screens , anti-reflex layer


the question says :- does the lcd screens really emitt less harmfull ray than the normal one ?


i have asked an (eyes doctor) , he didn’t answer me clearly about that :frowning: , does the antireflex layer on the sunglasses really help ?
is it a myth by commercial companys ?? ??
i really have to ask , i spend 7~10 hours daily at the pc :stuck_out_tongue:
thanks .

I’d love to come across someone can answer that! I spend about 7.5 x 5 days per week at it - less the holidays!


I’ve never heard that monitors project harmful rays!

Though, in the case of CRTs, I wouldn’t be surprised, but I doubt that it would be enough to do any damage even if you were on the computer for a year at a time.

LCD/Plasmas wouldn’t, because of the way they work.

But I’m skeptical about anyone’s claim that CRTs emit harmful rays, though I suppose its possible…

The original CRT screens emitted IR radiation. This IS harmfull to your eyes.

IIRC it wasn’t alot, so unless you were setting right in front of the screen there wasn’t really an issue (hence the whole square’d eyes thing your parents have probabily said to you).

However, because of this the screens were fitted with IR filters anyway.

It is possible for LCD/Plasma to emit IR light. This is, however, dependant on the back light used which is very unlikely.

It wasn’t just IR, the old CRT’s produced all wavelengths… including X-Ray!

It depends on the amount of shielding basically. A good 10 years ago I think, there were new emission standards and according to the Wiki, the ones still made are well below that.

There’s a question open about low-frequency RF. That is more likely to be emitted by LCDs because things like Xrays have to be very high voltage - B&W monitors hardly created any.

I believe that with LCD’s the main issue is the quality of the screen - fuzzy screens will wear out your eyes, and the strain could damage them. Take regular “screen breaks”, in fact, getting out of the chair for a few minutes every hour should be manatory, your legs & back need a break too.

ok well recently i was looking some of these things up and if you spend i cant even remember how much time in front of a crt then you get 50 or so mrem of radiation per year and just for comparison just by living on the colorado plato in the untied states you get 60 mrems a year and on average in the US you get 360 mrems of radiation per year and a dose of radiation that starts to deteriorate your cells and change the dna is about 5,000-20,000 mrems " so that 50 mrems over the span of the year will have almost no effect on your vision because it doesnt start to deteriorate your cells and plus there is some evidence to support that small amounts of radiation can even lower your risk of cancer but im not sure how reliable this last part is

About the “anti-reflex layer” on certain glasses that is normally just a filter which polarises light. So is it less harmful for the eyes… When light gets polarised it loses some of it intensity so the light has less energy. So it won’t screw up your eyes that much but you’ll see less. And my best guess would even be that it would be a marginal effect…

I’d worry more about using a CRT at less than 75Hz in combination with tube lighting (your brain does not appreciate this one bit, thus the head-aches, drowsiness and other weird symptoms).

Refresh rates should be above 72Hz for a CRT screen.

LCD screens are fine as long as you use DVI input above 1280x1024 (otherwise with vga it gets all blurry and makes your eyes water too).
I’m on average behind screens 10 to 12 hours a day. And taking a break to stretch is definitly advisable.
Best way to do this is either to get a cat, a dog, or a wife. Aquariums work too if you have to stare at something else than your monitor for a while. Best advice I’'ve heard so far if you can’t get a distracting biological life form in the house is to act as if you had one: going on a stroll is possible without having a dog.

LCD’s are definitely better on the eyes. I dunno about harmful rays or anything, but LCD’s are nowhere NEAR as bright. With a CRT you’re effectively staring at a lightbulb for 9 hours. LCD’s are also crisp and sharp all the time, assuming you are using it’s native resolution, and CRT’s can get fuzzy, especially as you move towards the edges of the screen. As a result your eyes can become strained by trying to futilely bring a fuzzy image into focus. They also now cost less to produce, use less power, weigh less and take up much less space than an equivalent sized CRT. And they taste better too.

Good point.

I know CRT monitors still emit radiation, but they have about twenty pounds of lead in them to stop the radiation. That’s why old monitors were way lighter, because they had no lead. Bu be careful, as there is no lead in the back. Do your best not to get behind a CRT monitor while it’s switched on. I know this because I did some volunteer work at a place that recycles old computers, and you actually have to pay to recycle your monitor because of the lead and stuff.

They also now cost less to produce, use less power, weigh less and take up much less space than an equivalent sized CRT. And they taste better too.

and tend to have to much contrast between colulrs.
and often come with all the seatings on max resulting in shades close to black looking like black.
and are usaly to bright which makes a dusk image look like brord daylight.

these are my observations anyway.

One thing I can say:
When I was standing in front of my old CRT monitor 5 hours on a rool, my head seemed to want Explode. The past 2 years I’ve been using one 24" LCD 14h by day and I’ts all Ok, so I guess that LCD’s realy nust be less harmfull :smiley:

Compared to old CRT’s maybe.

You can get cheap LCD screens and you can get cheap CRT screens.

LCD’s actually tend to give people more eye strain /head aches compared to their CRT counterparts. This is not to do with IR radiation etc…

The main problem with a CRT is that its resolution independant (several resolutions can be used /displayed without interpolation). This means people tend to pick the wrong resolution type for their screen size, and improperly calibrate the screen.

Additionally, a cheap CRT probabily would look fuzzy. Thats like me saying A cheap LCD /TFT screen looks mostly black and then looks inverted at every angle other than 0*

I think that this is good reason why an interface of any program should have some kind of background to relax you eye, and less tiny little texts and thousands of buttons for less strain. I think moi hit that right on the spot.

thanks …