Co-starring sunglasses and enhanced with LSD. From Bethany Jean Clement's review:

The mere fact that a movie is based on a book by Hunter S. Thompson does not mean that the movie must include LSD. In the case of the book The Rum Diary, the intoxicant of choice is, thoroughly, rum. LSD does not appear in the book, which is a fictionalized account of young Hunter S. Thompson’s drunk time as a journalist in San Juan, Puerto Rico, around 1960. LSD probably would have been very hard to come by in Puerto Rico around 1960, and yet a very down-at-the-heels character produces some, saying it’s what the CIA gives to communists and that you take it by eye-droppering it into your eyes (it is liquid acid, naturally). Then there is an obligatory scene where they wait, and nothing happens, and then his sidekick’s tongue grows hideously long (except it’s CGI, so it’s fakey-hideously long) while the young Thompson character, played by Johnny Depp, lightly freaks out. Having switched movies to Fear and Loathing in Las Vegas, Thompson/Depp then has a forgettable revelation while conversing with a lobster. Then we switch back.

Read the whole thing here.