"In fact, when the eye perceives bright light one of four reactions may take place. These are, in order of increasing brightness: dazzle, after image formation, flash blindness, and irreversible damage. Most individuals will have experienced dazzle as a result of oncoming car headlights and persistent after images from accidentally staring at the filament of an incandescent bulb. Both dazzle and after images will distort vision for some seconds to minutes. Flash blindness occurs when an extremely bright flash is discharged, usually at night, and again vision is temporarily lost. All three reactions would be useful in temporarily disabling a pilot and causing him to abort close approach to a target. If even higher irradiances reach the retina then irreversible damage may occur. In practice, a laser system that will dazzle at one mile may permanently blind at closer range."