Joy Chastain, M.D., Athens Dermatologist Dermatology logo for print

Joy B. Chastain, M.D., F.A.A.D.

Address: 1500 Oglethorpe Avenue, Suite 3000, Athens, GA 30606
Phone: 706-543-1335 • Fax: 706-543-1395

Joy B. Chastain, M.D., F.A.A.D. Melissa Cannon, PA-C


The daily use of sunscreen (or sunblock) is a fundamental part of a comprehensive sun protection program. Some patients use sunscreen only when they are in direct sunlight for a prolonged period, but even small daily doses of sunlight (for example, when taking out the garbage, walking to and from your car, etc.) add up over the course of many years. We, therefore, recommend that you apply sunscreen (or a moisturizer containing sunscreen) to all exposed areas of skin EVERY MORNING and that you do this ALL YEAR LONG -even in wintertime.

How to Apply Sunscreen Appropriately

One mistake some people make is not applying enough sunscreen, so use it liberally. You must also remember to apply sunscreen 20 minutes BEFORE sun exposure followed by reapplication every 2 hours during periods of direct exposure and immediately following swimming or heavy exercise. The sunscreen you use should have an SPF (Sun Protection Factor) of at least SPF 30 or greater. It should protect against both UVA and UVB rays. The "SPF" rating determines the amount of UVB protection you have but does not indicate the amount of UVA protection you have.  This is why you must also look at the ingredients in your sunscreen along with its SPF rating. Furthermore, be aware that the degree of sun protection provided by a sunscreen does not increase proportionately with the SPF number. For example, an SPF 15 sunscreen absorbs 93.3% of sun burning rays, whereas an SPF 30 sunscreen absorbs 96.6% of the rays, thus providing 3.3% additional protection.

Sunscreens are either physical blockers (ZINC OXIDE and TITANIUM DIOXIDE) or chemical blockers (Mexoryl-Ecamsule, Cinnamates, Avobenzone, Benzophenone, etc.). In general, the physical blocking sunscreens offer better sun protection and are less irritating to the skin. The following list includes sunscreens which are physical blockers that can be purchased at most drug stores:  CeraVe AM sunscreen, Coppertone Pure & Simple, Neutrogena Pure & Free, Blue Lizard, Banana Boat Kids.

In addition to sunscreen, we recommend that you wear protective clothing as often as possible. In particular, a hat with a wide brim (rather than a baseball cap) is helpful in keeping the sun off of your face, ears and neck. The following websites have a good selection of wide-brimmed hats specifically designed to protect your skin from the sun:,,, Amazon also contains many pieces of SPF protective clothing.