3. The effect of laser beams on the eye and skin
There is a primary potential hazard (direct or reflected laser beam) in the handling of lasers. This is due to the high energy density and low divergence of the beam.
The eyes are the most vulnerable to injury by a laser beam. A laser beam can cause damage to the retina or cornea or lead to permanent loss of vision.
Under some circumstances, the blinking reflex can provide some protection. When stimulated due to danger, the eye closes involuntarily within 0.25 seconds in awake, healthy and rested individuals. When one is on medication or under the influence drugs, the reflex becomes slower and as a consequence the beam is more hazardous than the given values. Moreover, there is no blink reflex in response to any light outside the visible light spectrum.
For the beam intensity decisive is, on one hand, the output power of the laser and, on the other hand, the distance between the laser and the eye. A “bundling” of the beams through the lens, may pose an additional problem for the wearer of prescription glasses!
Depth of penetration of electromagnetic radiation in the eye:
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