An interesting AskMetfilter thread inquires how filmmakers are able to make actor’s eyes appear dilated – to simulate them being dead – comes up with this answer:
Drops of belladonna in the eyes, apparently, is the old school way to do it. Here’s a note about it from the IMDB trivia page for Psycho:
Alfred Hitchcock received several letters from ophthalmologists who noted that Janet Leigh’s eyes were still contracted during the extreme closeups after her character’s death. The pupils of a true corpse dilate after death. They told Hitchcock he could achieve a proper dead-eye effect by using belladonna drops. Hitchcock did so in all his later films.
Other options mentioned include the use of cosmetic contact lenses and digital effects in post. But this response about the origins of using belladonna stood out:
Belladonna is named for the “beautiful women” who used to use it for this purpose; those beautiful Italian ladies knew that dilated pupils were a sign of sexual interest and they dripped it into their eyes to enhance their allure.
How necromantic.
…photo of Rumer Willis’ eyes via Evil Beet Gossip…