for the glasses question...valcar velcroed some lenses to the inside of his glasses against the lens...which i thought was a pretty neat idea, hed beable to give you some detail on that...
movie size is exactly that...movie size...some prop makers make bigger helmets and some make smaller...i believe boba makers are movie size, and sgt fangs are a little bit bigger....to fit your head into one, most people put either foam along the helmet liner area for a comfortable fit, or you could use a baseball helmet liner...or any kind of helmet liner really and just kind of tape/glue it in where its most comfortable to use