Yes, I Have A 13 Year Old Boy Who Has

Yes, I have a 13 year old boy who has been having eye pain, usually just one side at a time, but it goes back and forth between the eyes. His eyes have been checked and now has glasses but the eye pain is getting worse, they did not see anything wrong. He also is getting more headaches and gets lightheaded when he gets up, even when he gets up slow. What could this be?