Like the upper eyelid, the lower eyelid is vulnerable to bags, wrinkles, and sagging. Your wrinkles start as tiny lines underneath your eye, or maybe crow's-feet beside your eye. Unfortunately, those fine lines become deeper and more pronounced with time.
Also, as the orbital septum weakens, the fat pad in the lower eye pushes against the lower eyelid. But instead of creating a drooping hood, it results in puffy bags beneath the eyes.