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.
If you compensate or need assistance from a spotter, then the weight is too heavy and doesn't count. For example, if you weigh 100 lbs., you should be able to do one leg press with 180 to 220 lbs. on average. Less than this amount means your ability is below average.