Cut a few lemons and squeeze out the juice. Apply the juice with a cotton ball directly onto the acne scars on the face. Allow it to remain for some time and then wash with plain water. This tends to have a bleaching effect on dark scars. However, it is important that you avoid going out in bright sunlight when you have applied the lemon juice because it can cause darkening of skin. You can also combine lemon juice with other ingredients for scar reducing effect. Mix one tablespoon each of lemon juice, honey & almond oil with 2tbsp of milk. Apply this mixture on your scars once a day for about one week to see improvement.