Medical Skin Care > Understanding Your Skin > The Sun & You

The Sun & You

Healthy suntan? Certainly not!

The sun is the culprit for many of the aging signs of the skin, such as wrinkles, uneven pigmentation, skin laxity, and appearance of blood vessels underneath. After excessive exposure, there are a lot of free radicals floating around, damaging the skin functions, destroying the collagen, elastin, and skin matrix. More importantly, it can cause skin cancers! So it is a must to use sun-blocks to filter the harmful ultraviolet skin, in order to keep the skin healthy.
Sunlight consists of ultraviolet radiation, which can be divided into 3 sets of wavelengths:

• UVA             320 - 400 nm
• UVB             290 - 320 nm
• UVC             100 - 290 nm

The two types of radiation that we should be careful of are UVA and UVB, since UVC is mostly absorbed in the upper atmosphere by the ozone layer of earth.  However if it penetrates this valuable screening mechanism, it can cause grave cellular damage to tissue. UVA has a lower energy, but because of the longer wavelength, it can penetrate deeper into the skin and is responsible for the longer-term damages. UVB has a shorter wavelength but higher energy, and causes most of the sunburn. So when purchasing an sun-block, the formula need to be effective in blocking both UVA and UVB.