The theory is that a white sclera surrounding a darker iris and pupil helps people work out where everyone else is looking.

该理论认为，围绕在深色虹膜和瞳孔周围的白色巩膜帮助人们判断出其他人在看哪里。

youdao

It is true that one theory out there, emanating from the House Republican budget, is that you can do this without looking at tax revenues.

WHITEHOUSE: Press Briefing

What we are looking at here is not what theory says ought to happen: this is what actually does happen out in the real world.

FORBES: Why Keynesianism Doesn't Work: Part II