The Facts
Lasers are extremely dangerous because they consist of a highly concentrated form of radiation that has a great deal of potential energy stored within it. The primary danger that lasers pose to people comes in the form of ocular injuries. The majority of such injuries to the eye come when a laser is shone into a person's eye for a period long enough to cause permanent injury to the affected tissues. Laser safety aims to limit the frequency of such incidents as much as possible.
Misconceptions
Many people believe that lasers, particularly hand-held laser pointers and lasers at light shows, aren't at all dangerous. That simply isn't true. A standard laser pointer can cause serious eye injuries if it's shone into an individual's eyes for too long a period of time. In fact, permanent blindness can result from burns to the retina if one's eyes are exposed to laser radiation for too long.
Type
Improved laser safety in recent years involved the development of a rating system for lasers. Lasers are categorized in the system with a rating between 1 and 4. A class 1 is the least dangerous type and should pose little to no danger when used properly. A laser with a Class rating of 4, on the other hand, can burn human skin on contact and constitutes a serious risk even when used properly.
Function
Laser safety is used largely to help regulate the sale of dangerous lasers and to help protect scientists who are working in a lab environment around lasers. Protective eye wear is generally mandated along with strict adherence to exposure limitations. All of these rules and regulations, when combined, come together to form a protective process that is commonly referred to as laser safety.
Evolution
Laser safety has evolved steadily over the years as the strength of lasers and the underlying technology has changed rapidly. As lasers become ever more powerful, it's important that laser safety continues to evolve as well.
