Health Consequences of CRT Monitors? 306
DigiMan asks: "I was wondering, what are the effects of working on a CRT are on your health - long term. It has recently bothered me that EVERYONE seems to be switching to LCD's - I noticed that Bill Gates was one of the 1st people to do this, even when the cost was super high, and many, many government offices switched to the much more expensive LCD's - despite budget cuts and having to go with the lowest bidder strategy they operate under. Was this ONLY for style and space savings? Is there some health consequence that no one talks about publically. I know that they do emit very low amounts of X-Rays and have a 60Hz magnetic field as well as a 12.5 kHz electro magnetic field (for the raster scan). I work in front of typically 3, 19" CRT's for 12 - 16 hours per day at an average distance of 18". Can these magnetic fields cause Leukemia, or anything else? Is being behind the a cathode ray tube that bad for you?"
Mostly Desk Space (Score:3, Interesting)
For me personally, Yes. It's all about the style and convenience. I can actually see my desk now.
For our SOC personnel that are in front of multiple large screens for an entire 8 hour shift, I think it is a nice side benefit that they are not being bathed in magnetic fields all day.
But they still look cool and take up less space. Not too mention, generate a lot less heat.
You do make an interesting point about being behind multiple tubes. I believe most measurements are made from some distance from the front of the tube.
Once again in a scenario like a call center or in our SOC this would tend to be the case when you have rows of monitors.
They're always watching.. (Score:2, Interesting)
http://slashdot.org/yro/99/10/25/2039238.shtml [slashdot.org]
Well my equally invalid evidence (Score:5, Interesting)
Now I'm a computer junky, I use them all the time, at work and at home. Until about a year ago, it was always CRTs. I now have an LCD at work, but still a CRT at home (which I am soon going to replace with another).
So in my case, an excessive amount of CRT usage doesn't seem to have caused any nearsightedness. Also not being nearsighted is counter to my genetics, my mother and father are both nearsighted, as is my sister who doesn't make much use of computers and got her glasses much younger than I did.
Again, just a personal anecdote and not a valid representation of the overall situation, but it runs completely counter to yours. I know it's compelling to think your experience is representitive, but it's very often not the case. Trust emprical research, not personal anecdotes.
Re:Bad for your eyes (Score:3, Interesting)
Re:Bad for your eyes (Score:4, Interesting)
LCD's have a different sort of refresh, the 60 hz isn't really a big deal unless you're talking about a fast moving action game. CRT's work by zapping phosphorous spots with an electron gun, immediately after being zapped it begins to fade, to perhaps 50% brightness in 20ms, about the time the gun makes a return trip. So a CRT pulses in time to its refresh rate; and wouldn't you know it, the AC current pulses at 60Hz, means some kinds of lights will also pulse at 60 Hz. Put the two pulses together and the can create an interference pattern that will drive some folks bonkers, strain you eyes subtly, etc. etc.
An LCD pixel on the other hand works like a switch, the pixel is on, letting the back light through, until it is told to turn off. The 60Hz refresh rate only corresponds to how often the pixel "might" get told to change, there is no pulsing.
Of course these are some gross generalizations and I'm sure someone will pop up to tell me how I have it all wrong, even when I'm right.
Re:Probably bad for eyesight. (Score:3, Interesting)
Would you want to stare at a lit flourescent tube for most of the day? Would would expect your customers to do this? Well, a CRT is a flourescent tube, and a window with a white background is a fully-lit flourescent tube. Guess what this does to your eyes
The common white background is a visual metaphor for paper. But paper isn't a glowing flourescent tube. And note that publications that are often read outdoors (newspapers, paperback books) are usually printed on an off-white, beige paper. This isn't because the paper is cheap or anything; it's done intentionally to lessen the assault on readers' eyes in sunlight and other bright light. The publishing industry has understood this for decades. The computer industry can't be bothered, though, and continues to deliver systems in which nearly everything defaults to a bright white background.
The solution is to find out how to override this whenever possible. With browsers, you can set the background to a neutral grey or beige or pale yellow, and check the "Always use my colors" setting. This will work for almost all web pages, and will greatly lessen their assault on your eyes.
LCD displays are a lot better than CRTs. So far, they aren't quite as intense, which can cause readability problems in bright light, but it's easier on your eyes. Even there, though, it's still best to override default colors whenever you can, and use a neutral background. Web designers might not like this, but they have no right to assault your eyes by forcing a fully-white background color.
Zinc (Score:3, Interesting)
Guess what activity makes you lose 5 mg of zinc? Uh huh. At 3 times per day, you've used up your daily dose of zinc!
Re:The real reason: (Score:2, Interesting)
I am 61, with good eyesight, I still fly both fixed and rotary wing, and standing in as CIO in a hospital, for three months, I found a LDC on my desk and had it swapped for a 17" Sony Trinitron the next day, I far prefer CRTs
I also stopped the CRT->LCD upgrade aka waste-money program and when I got the RADIATION argument I had the Radiology department come into clustered areas with their sophisticated and calibrated radiation detectors and they could not tell a computer work area from the tea room, with a TV.
Re:Probably bad for eyesight. (Score:2, Interesting)
Whilst discussing his terrible affliction I speculated that my vision may still be intact as a result of a curious habit I've had ever since I was a child: Often, when I'm daydreaming, bored or contemplating a problem my eyes drop focus and my vision becomes blurred as I gaze vapidly into the distance. He looked at me like I was mental. "You just shift the focus of your eyes?" he asked, raising the finely chiselled brow above his.
I reckon that occasionally staring gormlessly into space, while perhaps not being my most attractive quality, has given whatever muscles, and other nanomadness that do the actual work in my eyes, a little break. Thus providing a little respite from eighteen hour electron burn. It happens when I masturbate too. It could all be down to the porn. Who knows? But has anyone else experienced repeated spontaneous ocular chillin'? (TRUE!)