The toothpaste can remove scratches from glass. First, you should clean the glass well and dry it using a lint-free cloth. Apply a dollop of toothpaste to a soft cloth and rub it into the scratch using a circular motion. After buffing for 30-40 seconds, wipe the toothpaste off with a damp cloth. Dry again with the lint-free cloth.
You can apply a small amount of non-abrasive toothpaste on some cotton wool and gently rub your lens in a circular motion, slowly buffing away the scratches. Baking soda can be used as an alternative by adding water and making it into a thick paste, making slow circular motions on the lens.