I saw a blue outline around a girls face today?

I was in my choir class and there were tons of girls sitting around, and then I noticed that one girls face was kind of outlined in a blue color. I asked my friend by me if she saw they same thing as I did, and she didn't. I tired focusing later on a different friend, and I just saw a really light almost invisible blue line along her nose.But I got a headache from focusing on her too much. lol This is weird because it happened to me before a couple of times. Is my eyesight getting worse? Cause ,I do wear glasses and I'm blind as a bat without them, I sometimes have to squint to see things better.