If you do not open the lenses container, please refer to the expiry date printed on the lable.If you open the lenses container, you shall dispose within the said period listed in the "Replacement Period" in product description, example 12 months. You can wear as many times as you want. Please dispose within the replacement period or after the expiry date on the label, whichever comes first.Please also take note that the 12 months replacement period is a maximum period you can use. After you opened the lenses, it depends on the frequency you used. It's wear and tear product, the more frequent you use, you shall dispose it in shorter period time frame. The longest you can use is 12 months. Says you used it every day, then we advise you to dispose it within 3 months.