A person's mind is something that can be quite fragile, particularly if the person happens to be [[BreakTheCutie a cutie]] in a CrapsackWorld. The iconic fragile thing in fiction seems to be glass - very shiny and very fragile. This leads to it and its shattering being used as a metaphor for an individual's broken sanity.

A popular variant of this is the HouseOfBrokenMirrors.


[[AC:{{Anime}} and {{Manga}}]]
* Occurs during Asuka's MindRape in ''Anime/NeonGenesisEvangelion'' at the end of a repeated montage.
* Played with in ''Anime/YuGiOh'', where the Other Yugi shatters Kaiba's mind after defeating him at the end of the Death-T arc. In this case, it's intended to give Kaiba a chance to ''regain'' his sanity as he puts the pieces of his mind back together.

* One of the most frequent images in ''Film/SuckerPunch'' is a glass breaking, once just before Babydoll's sister dies (from a light source) and the second time when [[spoiler:Blondie dies]].
* In ''Film/{{May}}'', the SanitySlippage of the title character is represented by the slow cracking of the glass case she stores [[LonelyDollGirl her cherished doll Suzie]] in. [[spoiler:It finally breaks when she takes Suzie to a school for blind children that she volunteers at, as they fumble in their attempts to get Suzie out of her case and cut themselves on the broken glass. [[WoobieDestroyerOfWorlds It's all downhill from there.]]]]

* One very well-known literary usage is in ''Literature/TheGlassMenagerie'', where the glass unicorn's horn breaking off symbolizes [[spoiler:Laura's breakdown upon discovering Jim's engagement]].

* In ''{{Narbonic}}'', [[spoiler: Dave]]'s glasses crack near the end, symbolizing [[spoiler: his]] descent into madness.

[[AC: WesternAnimation]]
* ''WesternAnimation/AvatarTheLastAirbender'': [[spoiler:Azula's SanitySlippage culminates in her destruction of a mirror while preparing for her coronation.]] Her real JerkassWoobie persona is revealed in full at this point.