The second reason has to do with mirrors. And once people hear it, it suddenly explains why streaks keep appearing no matter how carefully they clean the glass. According to many professional cleaners, bright bathroom lighting can actually make glass cleaner dry too quickly. The warmth from overhead bulbs—especially in smaller bathrooms—causes the cleaning spray to evaporate faster, which increases the chances of streaks forming before the mirror can be wiped properly.
That’s why some cleaners intentionally turn the lights off first. Not because they can’t see the mirror. Because it gives them more working time before the cleaner dries. And suddenly, wiping the surface becomes smoother, easier, and far less streaky afterward. Some cleaners even use slow zigzag wiping motions from top to bottom instead of circular scrubbing, since it helps prevent missed spots from blending back into the glass.
It sounds oddly specific. But people who try the trick themselves often notice the difference immediately. The mirror looks clearer. The streaks disappear faster. And the room feels cleaner overall. Try it out for yourselves!