Laser Distraction Hazards
In many cases the hazard from laser pointers is not that they may damage your eyes but that they might be bright enough to dazzle or distract you while performing a safety-critical task like flying an aeroplane or driving a car. There are no European standards for assessing laser distraction hazards but American flight zones can be used as a guide. The normal zone is limited by the maximum permissible exposure (MPE) and is the same as the laser safety nominal ocular hazard distance (NOHD). The other zones use the ‘effective irradiance’ which is the irradiance multiplied by a factor which accounts for the visual response of the eye. This is factor is 1 at 555 nm (yellowish green) and falls to zero in the UV or IR.
The flight zone limits essentially relate to the probability of distraction, glare and flash blindness in low ambient light conditions. Here, glare is an impairment of vision which stops when the illumination ceases, and flash blindness includes an after-image which impedes vision after the illumination ceases.
| Distances | Description |
limit |
limit |
| Normal Zone Exposure Distance (NZED) | At distances greater than the NZED the effective irradiance is dim enough not to present an ocular hazard but may cause flash blindness. |
Maximum Permissible Exposure |
Maximum Permissible Exposure |
| Sensitive Zone Exposure Distance (SZED) | At distances greater than the SZED the effective irradiance is dim enough not to cause flash blindness but may cause glare. |
100 µW/cm2 |
25 μJ/cm2 |
| Critical Zone Exposure Distance (CZED) | At distances greater than the CZED the effective irradiance is dim enough not to cause glare but may cause a distraction. |
5 μW/cm2 |
1.25 μJ/cm2 |
| Laser-Free Exposure Distance (LFED) |
At distances greater than the LFED the effective irradiance is dim enough not to cause a distraction. |
50 nW/cm2 |
12.5 nJ/cm2 |
Our LaserBee laser safety software package, includes a general flight zones tool which can be used to assess laser distraction hazards.
- Click here to request a demonstration copy of LaserBee