Tap target with wand 
The Impervius Charm (Impervius) is the incantation of a spell used to prevent a substance being affected by another to some degree.
- Hermione Granger used this charm during a Quidditch game in 1993 on Harry Potter's glasses to help him see better while playing during a storm. Although this helped a little, Harry still had difficulty seeing.
- Angelina Johnson also suggested using the charm for the same reason to her team when she was captain during the 1995–1996 school year.
- Hermione Granger also used this unsuccessfully during the 1998 Break-in of Gringotts Wizarding Bank when trying to protect herself, Harry Potter, Ron Weasley, Griphook, and Bogrod from the Flagrante curse in the Lestrange Vault.
Behind the scenes
- This spell may be related to the Imperturbable Charm, a spell used to soundproof an area and prevent anything from entering that area.
- In the Harry Potter films and video games, Harry and other Quidditch players use Quidditch Goggles to protect their eyes instead.
It is said that the Latin impervius means (and is the source of) "impervious"; although it is the source of the word, it is better translated as impassable, as in a mountain peak. "Impervious" is itself an English word, however, meaning "impenentrable, incapable of being influenced".