bat an eyelid

From bat (“flutter”), circa 1900.

• "When laptop computers first came out they were something of a novelty. These days, nobody bats an eyelid."
• "[…]he got the drop on Cox, the only time I had seen or heard of its being done — had his pistol out and stuck in Cox's face before Cox could bat an eyelid."
• "If you were to walk into a salon in America after a few 10–12 hour days of sweaty, dusty travel with no shower, you'd probably be politely asked to leave and not return until you've cleaned up. But here in a land whose resources and infrastructure cannot sustain such frivolity, the barber doesn't even bat an eyelid."
• "Dublin's not a bad place to be gay. Most people wouldn't bat an eyelid at public displays of affection between same-sex couples[…]"

• bat an eye
• bat an eyelash
• flinch

• bat one's eyes
• turn a hair