Peroxide cleaning is the best and healthiest method for removing organic deposits from contact lenses. The principle involves the release of reactive oxygen which interacts with macromolecules and breaks them into smaller, water-soluble pieces. The peroxide cleans the lenses, and a neutralizing disc must be dissolved in the lens case with solution. The chemical reaction turns the peroxide to water, and the lenses are clean and safe to wear. Peroxide based solution usually contains 3% of hydrogen peroxide.