Depending on the brand and type of lens you choose, most manufacturers recommend replacing your contacts every two weeks or monthly for optimal eye health and comfort levels throughout the day. It’s important that you follow your doctor’s instructions when it comes to replacement frequency as well as proper care and maintenance routines for your specific contact lenses in order to avoid any potential complications with long term use such as infection or irritation from build-up deposits on the surface of your eyes over time due improper cleaning practices.