The software would presumably know what you look like and can record your facial expressions and map it onto your avatar in real-time. There's technology now to create faces that never existed on a real person, and there's been technology for 15 years or so to do motion-capture of facial expressions and map it onto a computer-generated texture.

Plus I would hope that the big black glasses eventually give way to something sleeker, more akin to an eyepatch or sleeping mask.