Even with proper care, contact lenses (especially soft contacts) should be replaced frequently to prevent the build-up of lens deposits and contamination that increase the risk of eye infections.
Soft lenses have these general classifications, based on how frequently they should be discarded:
Daily disposable lenses — Discard after a single day of wear
Disposable lenses — Discard every month, two weeks, or sooner, as advised by your eye care professional at the fitting.
Frequent replacement lenses — Discard monthly or quarterly as advised.
Traditional (reusable) lenses — Discard every six months or longer as advised
Gas permeable contact lenses are more resistant to lens deposits and don’t need to be discarded as frequently as soft lenses. Often, GP lenses can last a year or longer before they need to be replaced.