FACT: Just because you can't feel the sun on your skin doesn't mean ultraviolet radiation isn't there. As you, say, walk to work on the shady side of the street, sneaky diffuse irradiation (scattered solar beams) present in the atmosphere during daylight hours accounts for a whopping 80 percent of your annual dose of UV exposure. "Sun damage is cumulative," explains New York dermatologist Dr. Debra Jaliman, so you simply must wear SPF 30 broad-spectrum sunscreen all year round. "Even when it's cloudy, the sun penetrates through," she says.
FACT: Here's where those with oily complexions get the last laugh. You may have cursed your T-zone in college, but oil naturally moisturizes and protects skin from aging. Dry skin shows fine lines earlier, no thanks to an impaired outer barrier that lets youth-preserving moisture out and aging irritants in. For dry types, Jaliman recommends a lightweight moisturizer with hyaluronic acid, a molecule that attracts water. (We like Neocutis Hyalis 1% Hyaluronate Refining Serum, $95.)