Laser safety eyewear used in USA, Europe is required to be marked with L ratings, Wavelengths and Optical Densities which are normally written on the lenses or on the frames.
L ratings are used to determine how long the glasses can withstand a certain level of laser radiation for a period of 10 seconds. Optical densities are used to determine how much the glasses cut down the laser power by and to the power of 10. An OD or Optical Density of 7 will cut the laser power down by 10 million times. An OD 3 will cut it down by 1000 times. The wavelength of the laser is normally specified in nm or nano meters and relates to the specific frequency of the laser.
If you would like assistance in selecting the most appropriate laser safety eyewear for your laser feel free to email us at firstname.lastname@example.org and one of our laser safety experts will be happy to help.
Alternatively you can find more information via the below free guide.