it has optical sensors but they don't point at the ground at its feet, they point ahead at the horizon. similarly, humans don't watch their feet as they walk, t

it has optical sensors but they don't point at the ground at its feet, they point ahead at the horizon. similarly, humans don't watch their feet as they walk, they look ahead at the horizon. making real-time adjustments to footing is a necessary part of walking. the sensors on the feet provide the data for these adjustments, but they are touch sensors, not optics.