Hi. Greetings. If your skin is" blackened " due to sun exposure, it's just because of prolonged tanning. Sun tanning can occur even with short exposures and this is a protective mechanism of skin. Don't worry, regularly use a sunscreen of high SPF around 30 - and reapply every three or four hours if exposed to sunlight for long duration. PLEASE NEVER USE BETNOVATE N OR OTHER OVER THE COUNTER CREAMS SOLD BY CHEMISTS UNETHICALLY... IT WILL WORSEN YOU'RE ENTIRE FACE. See a dermatologist near you for any further assistance. Warm regards.