Contact lenses are created with your vision and eye physiology in mind. While they may all look similar appearance wise, there are differences in the molecular makeup of the lenses that make them approved by regulatory bodies for daily use, weekly use, and some that may even be suited for monthly or even yearly use.
It's important that you follow the recommendations of your optometrist or ophthalmologist in the wearing schedule of your lenses, and to ensure you don't overwear them. Over-wearing lenses beyond the time frames in which they were meant to be worn, increases the likelihood of eye infections as well as potential long term issues with your eyes. You can think of the lens wearing schedule as an expiration schedule that you also are used to seeing with food products that have a best before date. Like those dates on food that help prevent food borne illnesses, contact lens wearing schedules are meant to also prevent eye focused diseases and infections of the eyes.
