These DO come with backs
Several reviewers mentioned that the earrings fall out and need backs to stay in.  When I received these (March 2019), there were two, clear plastics backs included with the earrings. The card that they come attached to had a cute saying ("good vibes only" or something), and these made a great gift. They appear to be good quality and the design is minimal without being invisible.
Rating: 5 stars