Daily Wear: Lenses prescribed for daily wear are to be worn only during waking hours, usually up to a maximum of 18 hours.
Extended Wear: Extended wear lenses may be worn on an overnight basis for up to seven consecutive days (six nights). You should wear your lenses on an extended wear basis only on the advice of your optometrist.
Extended wear lenses generally have a higher water content or thinner center thickness than other lenses and permit more oxygen to reach the eye. However, their use has been linked to a higher incidence of eye problems.