Any of these popular LEDs cause eye damage? What about with Red filters?

I noticed I get a headache sometimes after playing with my XM-L lights, but never had such a reaction from my MC-E and Cree R2 (no, not shining it in my eyes!).

Any possibility these LEDs cause any permanent eye damage?

What about the combination of a bright LED using a red filter?

Cheers:huh:

how exactly are you playing with xm-l light?

Some ways the light might cause a headache off the top of my head:

• You're staring into the emitter when it's on and it's too bright and possibly causing eye damage. Solution: Don't look directly into the business end of the light when its on:huh:.
• Low PWM - perhaps your XML light uses PWM to control brightness. This works by rapidly cycling the light on and off many times per second. On some lights the PWM is too slow and this strobing effect becomes noticeable and can cause headaches. Solution: Don't run your light on low modes or buy a different light that uses higher frequency PWM or uses current control to control brightness.
• Strobe mode - Playing too much with the strobe function many flashlights have could cause a headache. Personally, I hate having strobe mode on my lights. If a light has to have strobe mode I'd prefer it to be a hidden option like on the Zebralight SC51.oo:
• Cool color tint - some people report more strain when they use lights with cool color tints. Switching to a light with a neutral or warm emitter that looks more like natural sunlight may help.

Fireclaw seems to have hit the nail on the head. What light are you having problems with?

And for the red filter: I don't think this will do any more/less damage than the normal light. Perhaps you're comparing it with a laser light?

Do these and other L.E.Ds produce ultraviolet light to excite the phosphor? How about too much ultraviolet light escaping causing eye strain. Just a wild thought...

I don't think they emit any significant amount of UV light. I doubt someone would burn their retina with today's LED lights (unless you are the kind of person that likes to stare at the sun). As far as the headaches are concerned, my guess is it is related to pure output. Are you messing with your lights during the early evening or when it is pitch black out? Drastic changes in lighting will place more strain on your eyes (and face, think of your face muscles when you squint), so if you are messing with a bright light in a small room when you have night adapted vision, there is going to be a lot of strain.

I'd go with the pwm causing this. Which xml lights do you have, maybe we can find the pwm frequencies for them.