Brown spots, or concentrations of melanin on the skin, are known as age, liver or sun spots, or as solar lentigines. The skin produces melanin as a protective mechanism against harmful ultraviolet radiation, explains the CNN Health website. The only way to prevent brown spots is to avoid unprotected UV radiation exposure. However, the appearance of skin later in life is largely determined by such exposure before age 20, according to Aetna InteliHealth. However, UV radiation protection can still help prevent age spots, and help limit the size and darkness of existing ones.
Limit your exposure to UV radiation. Stay out of the sunlight as much as possible between 10 a.m. and 3 p.m. The sun's UV rays are strongest during these mid-day hours, according to the Cleveland Clinic. Stay in the shade when it's available, and use large shade umbrellas at the beach or elsewhere. Also, don't use sun lamps or tanning beds. Like the sun, these devices give off UV radiation that causes brown spots to form on the skin.
Cover your skin with clothing or accessories before going outside. Pants and long-sleeved shirts are beneficial, and clothing with a tight weave is most useful for keeping out UV radiation.
Protect exposed skin with sunblock. Use a sunblock with a sun protection factor, or SPF, of at least 15 and provide both UVA and UVB protection. Apply sunblock half an hour before going outside. Re-apply products every two to three hours, or after sweating or being in the water.