Lasers : Laser light is an extremely intense form of electromagentic radiation and its name is acronym for light amplification by stimulated emission of radiation. Lasers are used widely in industry and research laboratories. Their dangers stem from the enormous concentration of the energy of the laser into a very small area. These extremely short, concentrated pulses of light can cause severe eye damage. Both the cornea and the retina may be affected and permanent blind spots can be produced at the points where the lens of the eye brings the rays to a focus, thereby destroying the tissues at the back of the eye.
This focussing effect of the lens of the eye increases the intensity of the laser light by a factor of about a million (106)so low energy laser light can also be dangerous. In practice the maximum safety value is set at one-tenth of this figure. Additional dangers in the use of the laser stem from the very high voltages required to operate its source.