A while ago I heard something snap when a passenger opened the door that covers the mirror in the sun visor. After that the door would not snap open and turn on the vanity light. Then the same thing happened to the driver side. The mirror/door assembly can be popped out of the visor. There is a plastic pocket that holds the spring to snap the door open. The sides of the pocket crack, allowing the spring to move and then there is not enough tension to hold the door open.
Went to dealer to price out new visors and their parts diagram indicated just the mirror/door assembly was available. About $50.