The human eye (depending on the person) magnifies light 100,000-500,000 times. The inverse square law means that only minor variations in distance can have large differences in effective light (yes, laser irradiance conforms to this law of physics).
As the ICRC points out, the levels to "temporarily blind" are extremely close to the levels that cause permanent eye damage. Handheld rangefinders can and do make mistakes. Safety level ratings are based on a 0.25 second blink response. If the laser misjudges range for just that short of a time because there's an obstacle, unintentional electronic interference, or even incidental atmospheric reflection, the laser output could cause permanent injury.
Corneal reflex and fatigue. Not a lot of research there, but there are indications that while blinking increases in general, corneal reflexes decline which would drastically increase effective exposure. Fatigue is definitely something associated with combat.
Finally, this is NOT theoretical. The military has admitted to injuries to their own troops from its use proving it happens. They would NEVER willingly admit if an enemy were blinded as that would open them up to an international incident and lawsuits.
The human eye (depending on the person) magnifies light 100,000-500,000 times. The inverse square law means that only minor variations in distance can have large differences in effective light (yes, laser irradiance conforms to this law of physics).
As the ICRC points out, the levels to "temporarily blind" are extremely close to the levels that cause permanent eye damage. Handheld rangefinders can and do make mistakes. Safety level ratings are based on a 0.25 second blink response. If the laser misjudges range for just that short of a time because there's an obstacle, unintentional electronic interference, or even incidental atmospheric reflection, the laser output could cause permanent injury.
Corneal reflex and fatigue. Not a lot of research there, but there are indications that while blinking increases in general, corneal reflexes decline which would drastically increase effective exposure. Fatigue is definitely something associated with combat.
Finally, this is NOT theoretical. The military has admitted to injuries to their own troops from its use proving it happens. They would NEVER willingly admit if an enemy were blinded as that would open them up to an international incident and lawsuits.
https://www.icrc.org/en/doc/resources/documents/misc/57jmcz....
https://www.newscientist.com/article/mg21328516-400-should-p...
https://www.longdom.org/open-access/chorioretinal-injury-cau...