But since even the most glamorous tan reflects some degree of sun-damaged skin, dermatologists strongly recommend that tanning be avoided. The long-term results of excess sun exposure can be excess wrinkling and several forms of skin cancer. There are many sunscreen products on the market today, which contain a bewildering variety of ingredients. While important, this number doesn't tell the whole story about sun protection. In order to choose the best sunscreen and get the greatest benefit, a little information about their ingredients, and what they can and can't do, is helpful.
Sunlight is made up of both visible and invisible light.
UVB light is the type mainly responsible for sunburn, and is the type that the SPF number is concerned with. In brief, an SPF of 10 means that a person can spend 10 times the usual period in the sun before burning. But the SPF number tells nothing about the risk of damage from UVA, which can also cause wrinkling and skin aging, and increases the risk of the potentially lethal melanoma type of skin cancer. Thus it's harder to know how much UVA you're getting and for experts to gauge how much of a UVA screening ingredient is necessary for protection. Such products contain ingredients that absorb both UVA and UVB light.