It's easy to forget that the sun is so bright that it can burn us from nearly 93 million miles away. But when we are reminded, the experience can unfortunately be very memorable.

Sunscreen is a good idea for reasons other than just preventing sunburns, of course — though sunburns are the most immediate consequence of spending time in the sun without it. Researchers who conducted a survey recently published in the journal JAMA Dermatology found that preventing sunburns was indeed the most common factor in most consumers' decisions to buy sunscreen, though preventing skin cancer was a close runner-up.

Yet the researchers reported that many consumers focus on the sun protection factor, or SPF, which only protects from sunburn. The other two top factors that consumers considered were sensitive skin formulation and sweat resistance.

"Despite the recent changes in labeling mandated by the U.S. Food and Drug Administration, this survey study suggests that the terminology on sunscreen labels may still be confusing to consumers," the study authors concluded.

The sun shines down upon us with two main types of skin-damaging UV radiation, UV-A and UV-B. They both increase risk of skin cancer, but also damage skin in distinct ways. Conveniently, the "A" in UV-A stands for aging, as UV-A rays make skin look older faster. And UV-B, accordingly, has a "B" for burning.  There is such a thing as UV-C radiation, but the Earth's atmosphere acts as our sunscreen for that one — which is lucky for us, because UV-C radiation is the strongest, most damaging of the three.

Sunscreen works because it combines organic and inorganic active ingredients that reflect, scatter or absorb UV radiation. Early sunscreens looked much like white paint because of their inorganic ingredients, but nanotechnology has since made it possible to produce effective sunscreens that are completely clear. 

The higher the sunscreen's SPF, the better it protects against UV-B rays. But it tells you nothing about UV-A protection. For that, experts recommend that you look for sunscreens labeled as providing broad-spectrum protection.

The FDA revamped regulations for sunscreen labels in 2011, in an effort to emphasize protection against both types of UV radiation. The results of this recent study however suggest there is still room for improvement. It seems like doing away with the confusing label "sun protection factor" in favor of something more along the lines of "burn protection factor" would be a good place to start.

Photo by Erin Stevenson O'Connor | Flickr