Sunscreen.
We think we’re protecting ourselves when we slather up with SPF 30+, but did you know that most sunscreens only protect against UVB rays and leave us open to damage caused by UVA rays?
Wait, what? Let’s backtrack. Before we talk about what we need to be protected from, let’s define the different types of rays.
The sun is the earth’s source of light and energy. In order to provide us with the things we need to survive, the sun lets off UV radiation as a part of the light spectrum that shines down on earth. These UV rays are classified by length in three categories: UVA, UVB, and UVC.
UVA:
The longest of the waves, these are divided further into two categories (UVAI and UVAII). These waves account for 95% of the UV rays that reach the earth’s surface, and thus we are exposed to these rays often. UVA rays penetrate the skin more deeply than UVB rays, and contribute to pre-mature aging and wrinkling. It was not suspected until recently that UVA rays were harmful beyond the aesthetic, but it is now understood that UVA rays damage the middle (basal & squamous) layer of the skin and may even initiate skin cancer.
UVB:
These are the medium sized rays. They mostly reach the outer layers of our skin, and are the primary cause for sunburn and sunspots. All sunscreens provide UVB protection, most pretty adequately. Its intensity, unlike the constant UVA rays, changes depending on season and location.
UVC:
These rays are the shortest. So short, in fact, that most of them don’t even penetrate the earth’s atmosphere. As of now, no studies have pointed to UVB rays as a problem for our skin.