What determines the Maximum Permissible Exposure (MPE) level?

The Maximum Permissible Exposure (MPE) level is determined primarily by the wavelength of the laser, the duration of exposure, and the output of the laser. Each of these factors is crucial because they directly affect the energy delivered to the eye or skin.

Wavelength is significant because different wavelengths are absorbed by tissue in varying degrees. For instance, the human eye is more sensitive to certain wavelengths, meaning that lasers operating at those wavelengths can be more hazardous even at lower power levels.

Exposure duration is also critical; longer exposure times can increase the likelihood of damage to biological tissues. MPE values change with the length of exposure, as prolonged interaction with a laser beam can lead to thermal or photochemical effects.

Finally, the output of the laser, typically measured in watts, dictates the overall energy reaching the target area. Higher output lasers can deliver more energy in a short time, raising the risk of harm.

In contrast, aspects like user experience, the color of the beam, and distance from the emitting source do not directly determine MPE levels, though they can influence risk and safety practices. User experience might affect how someone interacts with the laser or adheres to safety protocols, but it doesn't change the biological limits for exposure. The color of the