On Wed, 15 Feb 2012 02:34:27 -0500, you wrote:

>1. It seems that some infrared LEDs also produce a very small amount of re=
d
>light. I powered some on, and looked at them directly for a few seconds an=
d
>saw a small amount of red light being emitted. Why does this happen?
>
>2. What are the effects of staring into a bright infrared LED for some tim=
e
>(about the brightness of a bright flashlight that you normally couldn't
>look at for  more than a few seconds)? Since you can't detect the light,
>you don't have that reflex to look away from the bright source. Does this
>damage the eye if you continue to stare at it for some time (longer than
>you normally could into a bright flashlight)?

It's not that the LED emits red, but some eyes have some sensitivity  to ne=
ar IR.=20
The problem is that as the eye sensitivity is low, the amount of IR enterin=
g the eye could be very
high, and can't be judged by the perceived intensity.

I doubt a normal 20mA LED carries any hazard, but high power emitters and  =
laser diodes could well
cause damage.=20

--=20
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