How to Spot a Psychopath

Coincidentally, two people just e-mailed me about two different kinds of glasses that're meant to make using a computer a less eyestrain-y experience.

First, the ones that might work. Second, the... other ones.

At the inventively-named EyeFatigue.com, you'll find $US24.95 specs that are, essentially, reading glasses. Mild lenses that make it easier for your eyes to focus close, and which will probably give you a headache if you wear them at other times.

This seems sensible enough to me; computer use is pretty close work, and focussing close for a long period of time, even if your eyesight is perfect, will indeed give you eyestrain. Glasses that turn your long focus into close focus can help, here, once you adapt to the fact that your eyes feel as if you're looking further away than you are.

The Eye Fatigue site also reassures me with its lack of pseudoscientific bulldust, and firm instructions to actually get a proper prescription - with separate measurements for each eye - before ordering, if you know what's good for you.

I Am Not An Optometrist; there may be something horribly wrong with this that I haven't thought of. But it doesn't look too freaky to me. Close-work glasses are generally useful things, and these look like well-thought-out ones to me.

Now, on to the fun ones.

I got a letter as follows:

I recently came across a web post by an elderly gentleman complaining of "frequent conjunctivitis, dry eyes, hard crystals in the inner corners, etc" when he uses his computer that go away when he goes on holiday. Looking around the web he found MelaOptix glasses from the Melanin Vision Center as a possible cure to the problem.

Are they on the level or is it another case of fuel line magnets, cure every disease in the world pills, or wooden volume knobs that make your stereo sound 10X better?

Lastly, he also posed this question:

"Is an LCD screen free from "bad" radiation, that is high-energy (HEV) sight-damaging stuff, in comparison with CRT?"

Could you comment?

Rob

My first guess was that the gentleman's problem was happening simply because he's focussing his old eyes on something close for long periods of time, probably blinking less, and possibly also looking upward a bit (dust in the eyes, more evaporation from their surface), or into a breeze.

(And the gentleman may go on holiday to somewhere with higher humidity than his computer room, too.)

People can become very uncomfortable without noticing while performing any engrossing task, and computer use definitely qualifies. Many people have suddenly realised, while playing a game, that they're freezing cold, very hungry, and desperately need to pee. Staring until your eyes are bloodshot is the same sort of deal.

Many people also set their monitors too bright. Modern screens, especially LCDs, have very high maximum brightness which is only necessary if you're competing with a brightly-lit room. Your monitor should, ideally, be no brighter than a sheet of paper in your lap.

For many consumer monitors, maximum contrast and zero brightness is a good setting. If you do that, and can then (just) see all of the gradations in one of those black-to-white gradients, you're pretty much done. If the darker colours blend together, you'll need to tweak the brightness up a bit.

Monitor calibration can get a lot fancier than that, but Contrast 100, Brightness 0 often gets you more than half way there.

(Oh, and set the refresh rate properly, too.)

My considered opinion of the MelaOptix glasses is that they're a bunch of bollocks. The only thing they don't do is the one thing that could actually help - aiding close focus. All of their other features are pointless, at best.

"Melanin" is a term that covers several pigments, not just the biological one they want you to think they're talking about. Even if they're actually bothering to put biological melanin in their glasses, though, there's no reason to suppose it does anything special.

Yes, orange-ish lenses can make things seem a lot clearer, especially in glary outdoor situations where stopping a lot of blue light will help young eyes see, let alone old ones. That's why ski goggles are so often orange. But there's nothing magic about any particular exact flavour of brown-orange pigment, no matter what those Blue Blockers infomercials say.

The Eye Protection Factor the Melanin Vision Center mention is, as far as I know, just talking about ultraviolet light. Given that (a) even cheap sunglasses these days commonly have very good UV blocking and (b) computer monitors produce no UV (they've got narrowband red, green and blue phosphors - that's it...), I believe the Melanin Vision Center are being deliberately misleading about the qualities of their products.

Since computer monitors already allow you to change their brightness and (unless you've got a rather old one) colour temperature, though, anything sunglasses could do for you can also be done with the monitor controls. And turning the screen brightness down makes CRTs live longer, too.

There is no reason for normal humans to wear sunglasses indoors unless, of course, they're doing it to look cool.

Regarding "bad" high energy visible radiation - neither LCDs nor CRTs emit such radiation. The broadest definition of HEV includes everything down to 530nm wavelength, which is green, so technically the green and blue phosphors do emit that kind of HEV, I suppose. But they ain't nothin' compared with the blue sky, which is not generally regarded as all that terrifying.

Some old CRTs genuinely do emit quite a bit of never-proven-to-be-harmful radio frequency energy, but they emit it from the back of the casing where the high voltage stuff is, not from the front. Old monitors, and some other gear like laser printers, also produce significant ozone, which is bad for your lungs if it's concentrated enough that you can smell it - but which is only even slightly worrying, in real world terms, if you're chronically exposed, like the poor dude with three laser printers blowing warm air into his cubicle.

If CRTs were made out of ordinary glass, they'd also emit a lovely drizzle of soft X-rays. To stop that, they're made from leaded glass, which eats all of that radiation.

You can still get a nifty static electricity crackle from a CRT monitor, which alarms some people. But that is also perfectly harmless.

So, in conclusion: Properly calibrated prescription reading glasses? Possibly useful for computer users. Cheap off-the-shelf drugstore reading glasses? Quite possibly much better than nothing, for people who have trouble with close work.

Goofy melanin shades that claim to protect you from radiation that monitors don't even emit? Save your money.

(It should also be noted that the melanin glasses cost more than three times as much as the non-fraudulent ones...)