I read somewhere that most people's lashes grow in a single row, and having two or more rows is an anomaly, but I don't know if that's actually true or just some nonsense the internet made up. That said, there would certainly be some variation in the direction they grow in, which two planes at a slight angle to each other might help capture. All theoretical, all course, I haven't tried out anything like that in practice.

-- I'm not mad at you, just Westphalian.