Laser pointer safety standards and classifications

The laser pointer basically complies with the "Laser Equipment Safety" standard, DINEN 60825-1 [DIN 03], to be classified. According to this standard, only Class 2 lasers should be classified as laser pointers that have been put on the market, and their power is limited to 1 mW. Just like that, it can be assumed that if the exposure time is less than 0.25 seconds, it is not expected to cause damage to the eyes. However, there are also laser pointers classified as 3R lasers on the market. In continuous operation, their power is limited to 5 mW. Laser pointers that are imported or brought from abroad will fall off, and they are becoming more and more popular because of their higher brightness. These laser pointers are very common and are marked as Class 3a (IIIA or IIIa) lasers according to the American Standard [ANSI 00], which corresponds to Class 3R lasers in DIN. If used for commercial purposes, these lasers may even be classified as potentially dangerous Class 3B lasers. Higher power laser pointers are regarded as definitely dangerous. Rough and dirty surfaces cannot accurately reflect the laser beam, but instead guide it to increase divergence, so that the power distribution across the beam's cross-section may also change. The increased divergence increases the hit probability, but at the same time the irradiance decreases due to the enlarged beam cross-section. If you look at the laser pointer beam through the window, the situation is similar. In both cases, the possibility of temporary glare is greater than retinal damage.