sunprotection is very important for black marks.
Use a sunscreen on regular
Creams containing kojic acid, arbutin, ahas, can help in lightening of the marks.
Dark circles basically occur due to nutritional deficiencys so replace them if present, than stress
, improper sleep, excessive rubbing should be avoided.
Treatments like peels, rollers, etc can help in lightening of both black marks as well as dark circles.