There's just no getting around it: If your eyes don't look healthy and bright, neither do you. Unfortunately, many common conditions and ailments can cause your eyes to appear red, puffy, or otherwise sickly, including:
Lack of sleep
Normal aging/cosmetic issues (bags, crow's-feet, etc.)
Of course, there are also anatomical issues at play here, namely the size, shape, and symmetry of the eyes, along with conditions like serious dark circles, which can be caused by capillaries surrounding the eye.
Since you see people every day of your life and you know everybody's physically different, you might wonder why the eyes play such a huge role in how you perceive somebody at first glance. A person's eyes can tell you many, many things about him: his age, his mood, his level of health, whether he's paying attention to you when you speak. Throughout this chapter, you'll learn how to interpret — and use — specific eye movements.