Can I use the headset while wearing glasses?

Yes. Typically you can use your headset while keeping your glasses on. But it also depends on the size of your glasses. When you have a wide model, you might find it difficult to fit your glasses in the headset. When this is the case, you can take off your glasses and use the focus option that is available on the headset. A Samsung Gear VR, for example, has the ability to compensate for -2(nearsightedness) and +2(farsightedness).