Just spray ALGI®-Brillenzauber "antibeschlag" evenly on the lens and leave it there for a short time. Afterwards remove it with a paper tissue and polish the glass. Use it about three times a week. Polish again after a few days if necessary with a micro fibre cloth. The set (spray & refill bottle) lasts for 1 1/2-2 years. The more ALGI®-Brillenzauber is used, the smoother the glass becomes. In this way takes up less dirt. It is not recommended to use other products (e.g.glass cleaning cloths, detergent, etc.) in addition to ALGI®-Brillenzauber.