In recent years, Laser Pointer have appeared in consumer markets around the world for sale for no more than $ 50. Consequently, their use among the general public has proliferated. The use of these laser pointers by untrained people, who are generally unaware of their potential dangers, occasionally results in the flash-blindness of a student or audience member. Some victims of this flash-blindness have occasionally had a furious reaction, leading to the development of the term “Laser Rage”.
Numerous claims of laser damage resulting from exposure to these beams of wavelength 635-670 nanometers (nm) with a few milliwatts (mW) of power have appeared in the press and on the Internet. The output power of the laser diodes in these 3000mw laser pointer is generally in the 3-5mW range, although some units are advertised with power greater than 5mW. By comparison, the threshold limit value (a commonly accepted occupational exposure limit) for exposure to lasers in this wavelength range is 2.5 mW / cm2 at the cornea, averaged over a 7 mm pupil. for a limited exposure time of 0.25 seconds. This is equivalent to a 1 mW beam entering the eye. Thus, an exposure to one of these beams can exceed. However, in most circumstances, when the beam is accidentally swept across the face and enters the eye only momentarily, the exposure would usually fall below.
The safest laser pointers are those that do not exceed 1mW of output and therefore will not produce exposures above the unless the viewer overcomes their blinking reflex and deliberately stares into the laser. These are Class 2 lasers and carry an Attention label. Lasers in the 1 mW to 5 mW range are Class 3a and carry a “Danger” label. Class 2 5000mw laser pointer, which have an output power of not more than 1 mW, are available, but those with a length of 670nm wave have low apparent brightness and may not be satisfactory for all uses. Laser pointers with a wavelength of 635nm produce much brighter red-orange light and are satisfactory for most uses, even when the power does not exceed 1mW. However 635nm pointers are a bit more expensive and are difficult to find. A company now markets a green laser pointer, but it is even more expensive. This pointer should appear very bright even at a fraction of a milliwatt So when such short wavelength diodes become cheaper and more available, this problem should become self-limiting.