system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How do flash grenades work?

How do flash grenades work, and would they still work if somebody closed their eyes?
gpt
Flashbangs are a type of grenade with a strong casing to remain intact during the explosion, so that bits of shrapnel don't kill people.  The explosion releases extremely bright light that activates all photoreceptors in the eye, causing a "burned in" image and temporary blindness for a few seconds.  Closing your eyes may dampen this effect.  However, it also produces a tremendous noise that deafens nearby individuals, and disturbs the perilymph (inner-ear liquid) which causes loss of balance and disorientation.  Closing your eyes doesn't stop this bit.