<5 mw 405nm ???

[Firsh]

Do you need goggles with a 20mw 405nm laser pen? How safe it is indoors? Can I look at the dot on a wall?

 

[NetGod3Com]

How much do you like your eyesight? Hit anything that retro reflects that 20mw beam back into your eyes and you risk damage.

When in doubt, whip it out (proper wavelength goggles that is.)

 

[anselm]

however, a 5mw laser can not do harm to your eyes. do not worry.

Except that a 5mW 405nm is virtually unheard of.
While advertised as <5mW, they are in reality 40~60mW.
All of the the ebay ones at least.

Be careful an never believe waht it says on the chinese lasers sticker.

 

[Krogith]

GUESS it is the same result with looking at the sun. We may feel lots of dots flaming ahead after we look at the sun for a while. The laser beam can cause the same result... however, a 5mw laser can not do harm to your eyes. do not worry.
Besides, the higher of the power, the more giddiness you will feel...

Anselm is right, I have bought more than a few pointers now and all the ones labeled at 5 mW are over spec some up to 60mW's

So be careful, The Chinese Sell "Supen Bnigkt" Lasers!!!!

 

[chipdouglas]

Besides, the higher of the power, the more giddiness you will feel...

this is horrible info. it can harm you. it is considers safe because the human blink relfex can react faster than you should get hurt. but you can definitely get hurt.

 

[Crazyk187]

What's the cheapest way to find out what the true wattage is???

 

[qumefox]

Send your laser to someone with a LPM. Next cheapest way would be to buy a LPM like the radiant alpha yourself.

 

[Bionic-Badger]

Maybe the urine on the wall is fluorescing. You should aim better next time.