[Laser radiation protection in medicine]

In medicine, lasers with different wave lengths are applied for therapeutic purposes. The human eye is especially endangered by laser rays with a wave length between 400 and 1400 nm. This is due to the fact that these laser rays are focused in the retina by the refracting media of the eye, so that the energy dose is considerably increased. If these lesions are situated in the most sensitive point of the retina, this may cause a markedly deteriorated vision. The necessary protective measures in the use of laser rays are based on a classification of lasers in four degrees according to the risk involved. The essential measures of protection are a shielding by filters, protective glasses and the determination of a so-called laser zone.