Map reading glasses. Very popular with orienteers requiring eye protection & magnification
Full glasses with bi-focal magnifier in lower part of lens help map reading while running
Supplied with a clear lens. Also good for cycling
Polycarbonate lens for good protection when running in the forest etc.
Diopter strength: +1.0, +1.5, +2.5, +3.0, +3.5 give good magnification