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.
1 When you're using weights, make sure to keep your back straight to prevent a muscle strain. Use the muscles in your legs to pick heavy weights up off the floor.  Use a spotter when you increase the amount of weight you're lifting above your body.