When writer Sergio G. Sánchez told the little girl who plays the blind orphan that she had pretty eyes, she replied, "Oh, do you like them? I picked them out myself!". What he didn't know: She was diagnosed at a very young age with a degenerative eye disease that was going to leave her blind. One of the last things her parents did while she could still see was let her see a big selection of glass eyes and choose the ones she wanted.
(at around 1h) Overawed at being in the company of acting veteran Geraldine Chaplin, J.A. Bayona broke the ice on her first day by hiding under a bed and grabbing her leg when she knelt down in the dark. Chaplin's scream in the film is one of genuine surprise.
Premiered at the Cannes Film Festival where it received a 10 minute standing ovation.
This scored the biggest box office opening for a film in its native Spain, outgrossing the similarly successful Le Labyrinthe de Pan (2006).
Although uncredited, Guillermo del Toro plays the doctor at the Emergency Ward who tends to Laura after she injures her leg.