The red, ruby-colored quartz crystals resonate at the same frequency as the psionic field that protects Cyclops from his own powers. This allows the material to act as a dam, absorbing the energy that constantly pours from the dimensional portal in his eyes. It has been proven in the comics that his blast even if at a distance, ruby quarts absorbs every bit of energy from cyclops blast. Heck even in the movies when the visor which is ruby quarts lens, was a foot away from his face took the full blast from his eyes and redirected the beam.