Lemons are a very powerful natural method for acne scarring. A natural exfoliant infused with citric acid is proven to help any scarring and dark marks disappear.
To use, simply dab some lemon juice on your finger or q-tip and apply directly to the scar. Rinse face after 10 minutes. If your skin is sensitive, add water to the lemon juice to dilute it. Try this method once a day for optimum results.