Any contact lens that’s worn for an excessive period of time, or longer than recommended, can lead to lens wear complications, such as injury or infection. Most people can tolerate wearing contact lenses for up to 16 hours per day. Never wear contact lenses while sleeping. For extended-wear contact lenses, the FDA recommends removing and cleaning lenses at least once a week. The maximum recommended time for continuous wear is 30 days. Never wear lenses for more than the wear time for which they were designed (for example, never use daily or weekly contact lenses as extended wear lenses).