A very light touch (+ a lick)

This is not a duplicate of "Single word for a very gentle touch"

I'm well aware of the variety of words for gentle, repeated or sweeping touch (caress, stroke, sweep, brush, rub, swish, graze etc.), but also of punctual, non-repeated touch with a certain amount of power applied (tap, dab, pat, tip, press, knock, poke etc.)

Yet, it's driving me nuts that there seems to be no English word uniting these two aspects, as there is in my native language Finnish -- a light, non-sweeping touch. May sound like a niche concept, but I find myself missing the word on a regular basis.

A "hipaisu" -- is an ephemerally light single touch, as though using a button on a touch screen with neither a tapping noise nor pressure applied.

("lipaisu" in turn refers to an equivalent act with one's tongue. Extra applause for figuring out a word for that too.)

Some examples:

"Holding her breath she approached the alien life form timidly with her hand, and _______ed its translucent skin."

or "As she kept her eye open with her fingers, the boy _______ed her eyeball and giggled."

You could surely use "touched on," which, however, fails to convey the timidity and gentleness of the act, besides being generic. "Tapped," again is too vigorous, and "stroked" too extensive.

Please, Stackers, help me out!

For your first sentence, "felt" (as in the verb "feel"). "Touched" would work given the setup you already have, or even "gently touched". "Gently felt" would emphasize the exploratory nature of it.

Instead of looking for a single word, try expanding the sentence to give the implied meaning you want.

"gently touched its translucent skin, feeling the strange texture under her fingertips."

Similarly, for the second sentence example: "the boy touched/felt her eyeball experimentally, and giggled."