Drink plenty of water. Include whole cereals, vegetables, fruits, pulses etc into your diet. Exercise daily to have good blood circulation.
Mix 2 teaspoon of milk, 1 teaspoon of honey, 1 teaspoon of lemon juice and half teaspoon of almond oil. Make a paste and apply this on the face.
Potato acts as a very good bleaching agent. Slice a potato and keep them over the face. This would lighten the marks.
Take equal amount of holy basil leaves (Tulsi), Mix with Lemon juice and apply on affected part.