BirdzEyewear New Wing Skydive Parasail Goggles Reduced Glare Blue Lens

Q: Can a pair of RX/prescription glasses fit behind these goggles?

No it won't fit. It will create a gap and air will flow freely defeating the purpose of the eyewear. It's very uncomfortable because the glasses will be pressed around your eyes. Also, the pressure to secure the goggles on to your glasses might cause the nose pad to slide in the inner portion of your eye.