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.
Do leg presses. You'll need a machine to do this exercise, but the results are worth joining a gym. Leg press machines allow you to adjust the amount of weight you use, so you can increase it as your thigh muscles get stronger. Sit back on the leg press machine and place your feet against the footpads.