I am new to lasers (and maybe a bit paranoid), so my question is, can just looking at the beam or the dot of a 405nm laser hurt the eyes? The power of the laser is 200mw, but it's from Dealextreme so it's probably less. Thanks for your answers
Welcome to the forum In the safety section there's plenty information on this. In short: with 200mW the beam or a diffuse reflection is safe to look at, although it may be uncomfortable. Looking at the dot up close (for burning or whatever) is probably not safe.
In any way a specular reflection or direct hit is definately unsafe and will damage your eyes, so I really recommend getting some laser safety glasses, just to be safe in case of an accident.
It's not hard to accidently shine the laser on something reflective like glass. Doing so could direct a high-power reflection of the beam directory towards yourself. Wear safety glasses, better safe than sorry, especially in the case of your eyesight.
i highely recommend you get glass's for any laser, all lasers can some how be dangerous, you only got one set of eye's that can be replaced, all safty should be taken serious.
405nm brightness doesn't well represent the power of the laser. It's not safe to even look at a 50mW dot at a close distance for too long; especially if you're pupils are adjusted for low light conditions.