You should change or replace your contact lenses as often as your eye doctor or optician advises, even if you don't wear lenses every day. For example, if you wear one day disposable lenses you must make sure you throw them out after you have worn them for one day even if they feel fresh. If you wear contacts longer that you are supposed to or overnight, if they are not made for sleeping in, you can make the chance of getting an infection much higher.
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