For a long time in film, theater, and television, when a work called for a character with a disability, it was the norm to cast perfectly abled actors in those roles, especially if the role was one of the leads (you still want to cast a big name star in the lead role, despite the character's disability, after all). This was such a norm that the casting of authentically disabled actors as disabled characters has only become more commonplace since the late 1980s, though normally such actors are in supporting or background roles. Related to Cast the Expert. See also Written in Infirmity.