Yes, some people wear both the glasses and contact lenses to show the fashion. Their lenses of the glasses have no prescription. The glasses are just the accessories. However, people will use to wear either eyeglasses or contact lenses in the usual state to help them get the clear vision. But now they want to show the unique fashion. Thus they wear in the new way.
It depends on different person. Some people prefer to contact lenses, but some people prefer eyeglasses. For me, i have bought eyeglasses and contact lenses. But i never wear both of them at the same time. Usually, i wear eyeglasses when i work, study, shopping, watching TV, seeing computer etc. But i prefer to wear contact lenses when i attend to party or some specially occasion. So, whether wearing eyeglasses or contact lenses depend on yourself.
Well, from what I can see, you are very interested in that question. Anyway, as a matter of fact, both glasses or contact lenses, are designed to protect our eyes and improve our vision in a natural way. Some people of course try to wear them at will and choose to change regularly. But some people are not supposed to wear contact lenses due to some particular reasons so you should make sure your eye health allows you to wear contact lenses.