You order single lenses 'per eye'. When you choose your lenses, the site will display the quantity of lenses that are available for purchase and the an estimate of the time period that they will cover, based on usual wear - for example; in the case of daily disposable lenses "1 box/1 months supply/30 lenses" or "1 box/3 months supply/3 lenses" in the case of monthly disposable lenses.