Eye Damage from a Laser Pointer

By Carlos Mano, eHow Contributor

Laser pointers are handy, convenient and fun. They can really make an impression--especially during a high tech presentation. Many people wonder if they are safe--especially if pointed directly into the eye.

Lasers
Ordinary daylight is composed of a chaotic jumble of different wavelengths of light--different colors going in different directions. Laser light is beams of light all exactly the same color, wavelength, and direction, which produces a remarkably bright light from an extremely small beam.

ColorThe first laser pointers were red, and the cheapest ones still are. The brightest lights for the energy are the green lasers because humans see better in the middle of the light spectrum. Blue lasers have only recently become available.

UsesBesides pointers, lasers have a million uses. They are used to line up fence posts, to hang pictures in galleries, to aim telescopes and to indicate where the bullet is going to go when lasers are attached to rifles.

Eye DamageThe eye damage caused by a laser pointer is a function of how strong the laser is and how long it is shown into the eye. According to Douglas A. Johnson, a senior health physicist and laser safety officer for Texas A&M University, a brief exposure to legal lasers is harmless. Prolonged exposure more than 10 second) of even the weakest laser could be harmful.

Sporting EventsLasers have been used by spectators in sporting events to confuse players on rival teams. In some countries, the use of laser pointers has been banned at sporting events.

Lasers and the LawIn the United States, all laser pointers must be registered with the FDA, and it is illegal to sell or promote a laser pointer with more 5 milliwatts of power. In Utah it is a crime to point a laser pointer at a policeman or at a moving vehicle. In 2009 in California a woman was sentenced to 2.5 years in prison for shining a hand-held laser into the eyes of pilots landing jets at an airport. The regulations that describe the dangers of lasers to the eyes in the US are ANSI Z136. These regulations, along with International regulations IEC 60825, not only describe the dangers of different types of lasers to the eye, they offer safety suggestions such as goggle use.