The 27-year-old star, who has been slamming fellow celebrities like Rihanna and Miley Cyrus on Twitter, said she underwent the procedure to remove a birth defect, Us magazine reported.
"I was born with a webbing in between my eyes. That was a birth defect that I had surgically removed! I've never been more excited!," Bynes said.
"I consider myself to be a hero to have suffered 27 years with a birth defect and to just now have it surgically removed! I had to share my story with you so the media would stop using old photos of me and stop writing lies about me having odd behavior when I was just embarrassed to share the fact that I had a birth defect."
Bynes is due in court on July 18 following her arrest on May 23, when she was charged with marijuana possession and throwin a bong out of her apartment's window.