Skin Cancer and Other Hazards of Sunlight A controversial lawsuit filed in Los Angeles calls sunscreen labels misleading, citing terms like "sunblock" and "UVA/UVB protection." Sunscreens repel most UVB rays (the shallowly penetrating rays that cause sunburn) but do not guard as well against UVA rays, which penetrate deeper into the skin and may lead to wrinkles and skin cancer. To protect against skin and eye ailments, such as melanoma, doctors recommend wearing protective clothing and limiting exposure to direct sunlight. Each year, over 1,000,000 new skin cancer cases are diagnosed in the United States.