I would second the recommendation for tinting the front windows. 20% will match the rears perfectly. If you are unwilling to tint the windows I'd still suggest you reach out to some tint shops in your area, they may have some "clear" tint with anti glare coatings that you could apply to the windows and or the rear view mirrors. You could also look into those films for laptops and tablets that reduce glare but I don't know how much that is going to cut down on headlights shining in the mirrors.
Also, you may not have your side mirrors adjusted properly if you are getting a lot of headlights at you. Your side mirrors should be adjusted so that you can not see any of the side of your car. Its an old habit to set the side mirrors so that you can see behind you and see some of your car in the side mirrors as well. Here is a link that describes the proper way to adjust your side mirrors:
http://www.caranddriver.com/features/how-to-adjust-your-mirrors-to-avoid-blind-spots
Hope that helps some.