パッと見って英語でなんて言うの？

"パッと見" - at a glance - judging by their appearance - look at (swiftly) パッと見何人か(見た目で国籍)わからない - I can't tell what someone's nationality is at a glance. - Just by looking at someone, I can't tell what their nationality is. - At a glance, I cannot tell what someone's nationality is.