Testing laser safety glasses requires a spectrophotometer and applying three steps:
1. Apply the material in question (the lens), to the spectrophotometer. The spectrophotometer will test the amount of light being absorbed against the amount of light being let through at different wavelengths. The amount being absorbed is a measurement known as Optical Density. See the diagram below for an overview on how a spectrophotometer works. Please note, the spectrophotometer depicted below is showing a spectrophotometer for visible light; different spectrophotometers test for different wavelength spans.
2. Find out what protection level is needed premised on your laser's output. Do this by looking for the recommended Optical Density (OD) of the particular laser, asking your Laser Safety Officer, or feel free to give us a call at 1-866-650-6926 and we can assist you with a free laser safety consultation.
3. Compare the optical density of your lens to the optical density required. If it is sufficient, it is considered safe. Again, please consult a laser safety expert, it is always best to be safe. Lasers can cause serious injury.