Wearing a face-full of Vaseline to bed will only grease up your pillow, your hair and your bed-mate. Although petroleum jelly is good for locking in moisture, it also blocks up your pores. When pores get blocked, the oil backs up in the follicle causing the follicle to rupture. Result – a pimple! So now you have wrinkles and zits. BTW, wrinkles are not caused by dry skin. (more on this later).