Laser pointers are intended for use by speakers during lectures or presentations. Pointer-like devices are also used in laser alignment, construction, industrial manufacturing and automotive repair, and as aiming devices for firearms.
Laser pointer hazards
The apparent brightness of a spot from a laser beam depends on the optical power of the laser, the reflectivity of the surface, and the chromatic response of the human eye. For the same optical power, green laser light will seem brighter than other colors because the human eye is most sensitive at low-light levels in the green region of the spectrum (wavelength 520–570 nm). Sensitivity decreases for red or blue wavelengths.
Direct beam exposure from a laser pointer can injure unprotected eyes. Even low-power lasers can cause glare, flash blindness, and after-image effects when used improperly. Injuries resulting from aiming a laser pointer directly into a person's eye are well documented.
If aimed at a person's eyes, laser pointers can cause temporary disturbances to vision. There is some evidence of rare, minor, permanent harm, but low-powered laser pointers are not seriously hazardous to health. They may be a major annoyance in some circumstances: A dot of light from a red laser pointer could be confused with a laser gun sight, causing panic and possible injury. When pointed at aircraft at night, laser pointers may dazzle and distract pilots, and increasingly strict laws have been passed to ban this.
Laser pointer classes
Class 2 and Class 3A/R laser pointers
Iowa State University allows the use of Class 2 and Class 3A/R laser pointers without prior approval.
Class 3B and Class 4 laser pointers
The use of Class 3B and Class 4 laser pointers requires the approval of the Laser Safety Officer.