With practice, contact lenses become easy to put into your eye and as a result, you get the benefits of clear vision without wearing glasses. However, keeping contacts in for longer than the recommended time can do more damage than good, as the contact can become dirty. It is important to know when it is time to change your contacts to prevent health problems in your eye.
Listen to the professionals. When you first order your contact lenses, your optometrist will examine your eyes and help you decide what lenses are best for you. There are contacts that you have to change daily, bi-weekly and monthly. As a general rule, it is best to follow the directions.
Look through your lenses. Bacteria can build up on contact lenses, especially after wearing them for a long time. This can cause the contacts to cloud your vision. To check if it is time to change your contacts, take them out of your eyes, rinse them with saline solution, and then put them back. If they are still cloudy, then you will need to change them.
Monitor your comfort level. Dirt and dust can get stuck under a lens; causing your eye to become irritated and sore. Try cleaning your lenses first: If they are still uncomfortable, there may be a scratch -- perhaps from a fingernail, or from dropping it -- and it will need to be changed.