Special care is required for optimum performance. When the inner lens surface gets wet it becomes soft and is more susceptible to scratching. Do not rub the lens when this happens. Blot the lens with a soft cloth to remove the moisture or allow it to air dry. When the lens has been thoroughly dried at room temperature, gently polish it with a soft cloth to remove any smudges. The inner and outer sides of the lens should generally be cleaned with clean water only. Rinse and follow the instructions above for drying.