Well, first, I have to say that it is dangerous to wear old contact lenses. And also, it will just hurt your eyes. According to some experts, old contact lenses can contain a lot of virus, and bacteria. And in that way, it will just cause some eye problems. For example, it is possible to cause styes when you wear old contact lenses, for wearing old contact lenses may make your eyes infected. And then, it is easy for your eyes to have styes. Also, watery eyes, pain, tenderness, itching, or redness can be possible too. So in my opinion, you are not supposed to wear old contact lenses.