Whiskers are part of the total look of the cat, and most cat owners like them. But occasionally an owner will notice a wild hair (pun intended) and decide to trim the cat’s whiskers, the same way we trim our own whiskers and eyebrows. No permanent harm is done since they do grow back.
However, trimming whiskers should be avoided because they are the cat’s “antennas”—her sensitive feelers of the world around her—and are especially needed in the dark. There is even a kind of “whisker reflex”: in the dark, if something brushes against the cat’s eyebrow whiskers, she will shut her eyes immediately to protect them.