I know someone who doesn’t blink when something flies at her face.
She has worn glasses all her life, and one day her friends noticed: a hand coming at her eyes, and nothing. The reflex everyone else has, missing. The obvious guess: after a lifetime of lenses catching whatever came her way, her brain stopped bothering.
Can glasses switch off (or never switch on) the protective blink? What I found so far:
- That blink has a name: the menace response (blink to visual threat). It’s not the corneal reflex, the blink when something actually touches your eye, which glasses wouldn’t touch at all.
- The menace response isn’t a simple nerve loop: it goes through the visual system and the brain, which is why neurologists treat a missing one as a clue, not a diagnosis.
- Blink responses habituate: repeat a harmless stimulus and the response fades. So the glasses idea is plausible: years of things “hitting” a lens that always protects you could teach the brain that approaching objects aren’t a threat.
- But I found no study on glasses wearers and the menace response. For now it’s a plausible hypothesis, not a documented fact.
What would settle it: comparing the threat-blink in lifelong glasses wearers vs people who never wore them (or before and after switching to contact lenses).
Know a study like that? Send it my way, you’ll make my day.