Spread on Lemon Juice
Lemon juice is said to have a natural bleaching effect, thus it can lighten any scar including acne. You can mix equal amounts of water and lemon juice and put it directly on the scar. You can then rinse it off after 15 to 20 minutes or let it stay overnight. Since lemon contains citric acid, it can dry your skin so make sure you moisturize afterwards.