This is how I've always understood it:
Grab a standard flashlight and turn it on. You've got a beam of white light.
Now grab a red color filter or a piece of cellophane and hold it over the flashlight. The beam of light is now reddish. That's the only difference between a red-colored concussive force beam and non-red one. Granted, your flashlight isn't projecting a concussive one, but Scott's ruby quartz glasses are dealing that part of the equation.
The optic beams aren't opaque, just as light coming through a filter isn't. He would see things similarly to how he sees things through his glasses/visor even without them.
I don't believe they've ever explained exactly how or why the ruby-quartz counteracts the optic blasts. But the fact that he can wear seemingly normal ruby-quartz eyeglasses without them being strapped to his head indicates that whatever/however it does it, the beams are weakened to nothing. That means no concussive force is bouncing around behind the glass.