Wearing contact lenses for prolonged time

According to wearing schedules, contact lenses have two types: daily wear and extended wear. The difference lies in that extended wear requires no removal before sleeping so that they can provide a clear vision as soon as you wake up. Extended wear contacts are designed to permit more oxygen on the cornea, which should get prior approval from FDA. While most extended wear contact lenses are made for continuous seven days wearing, silicone hydrogel-made ones can last up to 30 days without removal. This type is also available in RGPs. Thanks to technological improvement; extended wear contacts are comfortable during the full time period.