Regular Rx glasses are not adequate as twigs, branches and debris can easily get behind them and cause serious injury. Once my Rx metal frame glasses put a gash in my temple when I did a face plant. Riding glasses are snug to the face to keep twigs and branches from getting behind them and hitting the eye. They curve around to protect the eye from the side, and have a soft nose piece and plastic frames so if you do have a face plant, the glasses will be less likely to cause an injury. This can quickly end a riding career.
Hard pads are optimum.
BMX stores carry many different styles. They go on and off easily. I was wearing soft volleyball type kneepads on my elbows, but I found that they just didn t give me enough protection. They are meant to be worn under BMX suits, so since I m wearing them external to any clothing, the articulated knee part will flap. I cut a section of the leg from a discarded pair of my wife s panty hose and pulled them over the knee to hold the pad securely.