Blemishes on face are one of the common signs of sun damage or ageing. Simply apply lemon juice mixed with honey and a pinch of turmeric on your face. Leave it for 15 minutes before washing it off. Do not expect dramatic results overnight. But, if it is a problem that has persisted for a long time, do consult your dermatologist. They will surely prescribe you some acid peels, products with hydroquinone or kojic acid.