Chinese laser pointer

[Leigh Palmer <palmer@SFU.CA>]

> Is it really true that visible light cannot damage the eye?
>
> The amount of damage that the eye will get if hit by EM radiation depends
> solely on the flux that will hit the retina. UV light is more dangerousfor
> two reasons. In the first place it has a high frequency and therefore high
> energy photons, in the second place wecannot 'see' UV light, therefore our
> pupil does not contract when hit  by high intensity UV radiation. So UV
> radiation is more dangerous, but so is visible light or gamma rays or
> infrared, you just need a big enough flux.

Today I saw a really bright laser pointer for my first time.
It is green (532 nm) and more than a milliwatt, but less
than 5 mW. It cost C$400, and its beam divergence is somewhat
greater than that of a normal red pointer (or else my eyes
are just seeing much farther out in the wings). I sure would
not want that flashed in my eye, even though I know it could
do no permanent damage.

It is a doubled YAG laser from China. Have you played with
one yet, Herb?

Leigh