Is there a way to get rid of the glare on the glasses?
I assume you mean in camera, not with retouching, right? With a light source fairly straight on, most glasses are going to reflect. Sometimes (particularly with lenses with non-reflective coating or weaker prescriptions), just a small adjustment like angling them slightly downward will do the trick. Or you need to move your light source off axis (sides or high in the air) so that the reflections aren't visible from your straight-on view.
Also, if you have them face a white wall and move off axis, there will be very limited reflection
It really is all about the angle. Keeping the glare off glasses is my biggest challenge when shooting people. I just have to angle the light or angle my subject so that the light isn't creating that glare.
If that seems impossible or if I can't seem to "make it work", I will take a picture of the subject without their glasses and then do a little photoshop magic to cut out the glass & glare from the glasses and replace it with the the same area from the no glasses pic. It's more work and I hate doing it, but sometimes that's what you have to do.