Air Optix Night and Day Aqua contact lenses can be worn around the clock for up to 30 days with your doctor's approval. Oxygen, smooth lens surface material, and moisture come together to form a protective barrier for your eyes keeps them well hydrated for a month. With a strong resistance to lens deposits, you can be sure that Air Optix Night and Day Aqua lenses will keep unwanted build-up from accumulating around your contacts. Desired comfort is achieved with a constant supply of oxygen that is allowed through the lens to reach your eye. The Air Optix Night and Day Aqua lenses allow you to take them out at night, or wear them while you sleep, for up to 30 days before switching to a new pair.