The incidence of flash blindness is the most common injury caused by lasers. This would happen if the eyes were to be exposed to a highly intense light flash for several seconds or even minutes. And the damage can be either temporary or permanent. Flash blindness can get even worse over time, especially for anyone regularly involved in visually-demanding jobs, like driving vehicles, for example. There have been multiple documented incidents of Pilots suffering from flash blindness caused by lasers intentionally Pointed at them from the ground. The damage that happens to the retina caused by the lasers can lead to permanent blindness. To prevent any incidents from happening, the laser level should be set appropriately. The laser beam on the laser level can cause irritation to the eyes if they were to ever be exposed to it occasionally, but there usually won't be any case of permanent eye damage (like the camera flash). In any case, looking directly at the laser for a prolonged period of time is something to be avoided. It’s worth noting that laser products such as levels are classified into different categories and have warning labels to alert users.