Did you know that sleeping is the second cause of wrinkles? One surprising cause of premature wrinkling on the face and décolleté (chest) is sleep, or more precisely, the position of the body during sleep. To prevent the crepes between the breasts, marionette lines around the mouth and wrinkles around the eyes, try to get in the habit of sleeping on your back. After the sun, sleeping on the side is like ironing wrinkles into the skin. This means that on average, you’re spending more than 2,500 hours per year potentially reversing the positive effects of your skin care treatments.