This is an extremely important question to ask. UVA rays from the sun are one of the primary culprits of melanoma. Melanoma is usually, but not always, cancer of the skin. If left untreated, it can spread to organs and other areas of the skin. Due to it being visible, it is easier to detect than most other cancers however, if it is given the time to progress, it can prove very difficult to treat. Therefore, you want to know which type of sunscreen you should use in order to get the best protection for your skin.