Bollywood appears to be inclined towards exploring rare illnesses/disorders/disabilities, with directors casting megastars in characters to raise awareness about the lesser-known ailments. In Ghajini, Aamir Khan had short-term memory loss [Anterograde Amnesia]. In Paa, Amitabh Bachchan played a child afflicted with Progeria. In My Name Is Khan, Shahrukh Khan was shown suffering from Asperger Syndrome. In Taare Zameen Par, Aamir Khan portrayed problems of Dyslexic children. In Black, Amitabh Bachchan was shown succumbing to Alzheimer's. In Karthik Calling Karthik, Farhan Akhtar portrayed a Schizophrenic.
This is not the first time that master film-maker Sanjay Leela Bhansali has attempted a movie that has the protagonist suffering from a serious disability. In Guzaarish, Hrithik Roshan suffers from Paraplegia, a complete paralysis of the lower half of the body, including both legs, usually caused by damage/injury to the spinal cord.
Bhansali has always been known for two things. The first thing is, of course, the visual splendour in his films [which was quite evident in Hum Dil De Chuke Sanam, Devdas and Saawariya] and the second thing that he takes inspiration from various stories. The critically acclaimed Black was inspired from The Miracle Worker [a 1962 film] and Saawariya from 'White Nights', a Russian short story.