Laser beams can damage tissue

The danger of a laser beam is that it can concentrate a great amount of radiation energy and power in one small area. The power of a laser beam attenuates very slowly over distances.

A laser beam does not intrude deep into tissue, which is why its ill-effects mainly consist of damage to the skin and different parts of the eye. A beam hitting the eye can be dangerous.

The most damage caused by lasers hitting tissue is the heating. Laser radiation energy absorbs in the tissue causing local and very powerful heating. The scale and severity of heat damage can range from a reddening of the skin to serious burn injuries.

A laser beam hitting the eye can cause permanent damage to the retina, because the beam focuses on a very small spot on the retina. This spot receives such large doses of energy, burning the cells of the retina so badly that they are unable to recuperate.