Answer Wiki. The system would be cued off the pilot's helmet, so it will definitely look where your head is pointing, not your eyes specifically (that would be a gaze-tracking system, which AFAIK hasn't yet been used for this kind of application).
Exercise to Gain Leg Weight. Although you can't make your body gain weight in your legs, you can perform exercises that encourage the growth of leg muscle. Squats, lunges and step-ups are examples of such moves that target the legs and recruit a lot of muscle fibers for growth.
The straight leg raising (SLR) exercise is a simple way to get your quad muscles working properly. Here is how the SLR is done. Lie on your back on a flat surface. Bend the knee of your uninvolved leg (the one that wasn't operated on) to a 90-degree angle, and keep your foot flat on the surface.