Note that you literally can't see anything that close to the eye. Normally the reason you reflexively close the eye and flinch is that something touches your eyelashes; I'm not sure if you'd have any reflex if something touched your eye without touching eyelashes.
But, say, a fine needle not mounted on anything and coming in from the side? Depends a lot on the light I think. Unless you have light sharply reflected from the needle (we're really good at detecting bright spots) you may well not be able to.
@robryk@VE3RWJ@mjg59 Biological vision is pretty complicated. We can see individual photons in some circumstances. We can miss large, clearly moving objects in others.
Body horror
@robryk @VE3RWJ @mjg59
You see *something* but no details.
But, say, a fine needle not mounted on anything and coming in from the side? Depends a lot on the light I think. Unless you have light sharply reflected from the needle (we're really good at detecting bright spots) you may well not be able to.