However, these pointers can be misused, for example, by students in classrooms or by children at home, and this has generated safety concerns. There have been reports of temporary blindness, disorientation and headaches by bus drivers, airline pilots, police and teachers. Manufacturers are now using similar low powered laser devices in toys. Laser light Lasers produce radiation, more commonly referred to as light, with unique properties that distinguish laser-produced light from light from more familiar sources such as the sun or common domestic lamps. Domestic lamps emit light that is highly divergent, i.e., that spreads out almost equally in all directions from the lamp.
Lasers can also produce a very narrow beam that diverges little.
This low divergence means that laser light is highly directional, forming a pencil-like beam and appears as a small spot when shone onto a surface, even at distances of hundreds of metres. As a consequence, high power lasers can be hazardous to the eye over considerable distances. Because laser light is monochromatic and basically low-divergent, the beam is better focused by the lens of the eye than any other light source, thus producing images on the retina with much greater intensities than is possible with domestic lamps. The visual response of the human eye is wavelength-dependent and is at a maximum at around 550 nm and decreases at higher and lower wavelengths. As a result, the human eye perceives the red spot produced by a laser operating at 635 nm as being about 10 times brighter than the red spot produced by a laser operating at 670 nm, even though each device may emit the same light power.