[MultipleParadox]

A note about what I think is a myth concerning low-powered green (vs red):

Yes low power red laser are considered harmless like stated above; but be more cautious when it comes to green.

Green lasers work in a totally different way than red: An infrared diode is used instead of a red one, and its light is passed through different crystals to change its wavelength and get the green. The process reduces the light's power significantly and as a result, to achieve let's say 5mW of Green light, you need a much stronger infrared one.

High quality laser will have good IR filters and won't pose much problems, but as most of people prefer to not spend their paycheck on a low powered laser, we end up buying cheap chinese stuff. In these the IR filter is mostly non-existent or ineffective, and will allow a good amount of IR light outs, which can pose a threat to you and others. Even more so considering this light is invisible but can still cause damage.

Be even more careful when buying cheap, high powered green lasers.