heinbloed said:One thing still: A laser should not be used in public for safety reasons,it can destroy the sight even when the eye is exposed only for a short moment.
Untrue, lasers come with different classifications indicating their power and ability to inflict biological damage. [broken link removed]
Class I lasers are low powered devices that are considered safe from all potential hazards. Some examples of Class I laser use are: laser printers, CD players, CD ROM devices, geological survey equipment and laboratory analytical equipment. No individual, regardless of exposure conditions to the eyes or skin, would be expected to be injured by a Class I laser. No safety requirements are needed to use Class I laser devices.
As it is a highly collimated beam of light the risk is that it can be focussed by the lens of the eye to a tiny point thus increasing its energy density dramatically - this can damage the retina.
Regardless of laser classification proper safety controls should always be used as good practice.