Well, generally speaking, the keratitis can not heal it by itself. And you need to take some measures to treat it. As we know that keratitis is the general term for anything which causes the surface of the cornea to breakdown. So it can be contagious. So just be careful about it. To treat it, antibacterial, antifungal, or antiviral therapies which can treat the infection are usually used. For These treatments, it can involve prescription eye drops, pills, or even intravenous therapy. Besides, if you are wearing contact lenses, you are not supposed it again, for it can just make the situation worse. Anyway, it can take about it one week to cure it.