PS here is 2017 Laserpointersafety link that discusses a new laser safety concept, the Nominal Ocular Dazzle Distance (NODD) concept and how to calculate it.
“The MDE is the threshold laser irradiance at the eye below which a given target can be detected. It can also be used as a measure of the minimum laser irradiance required to obscure a given target.”
“The NODD is the minimum distance for the visual detection of a target in the presence of laser dazzle. It also represents the maximum effective range of a laser dazzle system designed to prevent the visual detection of a target.”
See: Laser Pointer Safety - The Nominal Ocular Dazzle Distance concept
Very informative.