This is a hack that can be used for good or evil. You may have a good reason for needing to see through a frosted glass window, or you may be Penn Badgley’s character in You. The hack works either way.
Redditor UnableNefariousness, who I will assume is an upstanding citizen who would never use this hack for nefarious purposes, shared a video to r/BlackMagicFuckery. That’s the perfect name for this subreddit, if this video is a good sample of its contents.
In it, we see someone rub a small piece of clear tape onto a piece of frosted glass. The tape forms a perfect see-through rectangle through the frost.
How on earth does this work? Here’s the science, from piterrogulski:
The frosted effect is created by making the surface rough - it’s not flat anymore, so light passing through the pane gets scattered in all directions. Sticking a tape onto it fills the surface with the glue, making it smooth - light can pass in a more or less straight line
If you’re planning to examine all your bathroom windows to see if anyone has been peeping on you, there is some good news from Mr0lsen. The bumpy side usually faces in:
Only works from the textured side, which is almost always on the same side as whatever is supposed to be obscured.
So, maybe this is more of a hack for people who like to look outside while taking a shower or discreetly check who’s at the door. Sorry, creepers.