Blepharitis can be contagious. But you do not have to leave your classmate alone because she must feel uncomfortable and fragile due to the blepharitis, if you desert her at this time, she can feel lonely and depressed. As an old saying goes that a friend in need is a friend indeed, doesn't it? I think you should encourage your friend. Also, you should keep your own eye hygiene and wash your hands and face frequently. As long as you do not use your classmate's towel or give your towel to her, you can avoid suffering from blepharitis.