When my 15 yr old was very young... only a few years old, she has a pea size lump on her left eye just below the eyebrowl tward the outside if the eye. It was just a soft tissue mass - nothing big. Neve did bother her, but it did effect how her eye would open. It always looked like she was squinting... she did eventually have to have it removed, but doctors waited to see if it would go away on it's own first. Sometimes they do, sometimes they don't... hers didn't. It only took a few minutes and she didn't even need stitches, just a butterfly strap. And was healed up in about a week like it was never there.
Just keep an eye on it and keep talking to the doc about your concerns. It may go away in time or it may need removed - but they won't have removed my daughters if it wouldn't have been a possible vision issue. Just so you know it her was an actual round ball of tissue in between the layers on skin that make up our eye lid. And no one could tell us why it was there or if it will come back someday, but it hasn't so far.