Quick trivia: the thickest skin on the body is on the palms and soles, up to about 1.5 mm, while eyelids are among the thinnest at roughly 0.05 mm. That difference is exactly why we calibrate lasers and chemical peels by location in cosmetic dermatology.
I learned this the hard way with a home exfoliant: what felt fine on my cheeks barely did anything on my heels but zinged near the lids — “palms/soles” really are built-in armor. Small caveat: calluses and chronic rubbing can thicken spots over time, so patch-test by area to avoid surprises.
But climbing turned my palms into built-in gloves, so I’ve seen that “thickest” skin get even thicker, while a mild peel near the lids can zing. Caveat: thick skin isn’t tougher against UV — eyelids still need careful sun protection. @zjones070 your story tracks; I just patch-test on my inner forearm first.
I use a quick knuckle test: if something feels fine on the big knuckle but bites on my heel, it’s not going near the eye area. @zjones070, calluses can throw off the whole thick/thin rule, so I adjust expectations based on how rough my palms and soles are that week.
And funny side effect I’ve noticed: my phone’s fingerprint reader stops recognizing me after a kettlebell-heavy week because my fingertip skin gets a little tougher. Thickness doesn’t equal tolerance though — something that feels fine on fingertips can still tingle around the brow. @rlee303, I usually switch textures by area (silky gel for delicate spots, richer cream for tougher ones) rather than cranking up strength.