For any given substance, the heat capacity of a body is directly proportional to the amount of substance it contains (measured in terms of mass or moles or volume). Doubling the amount of substance in a body doubles its heat capacity, etc.
Conventional soft contacts can last up to a year; conventional rigid gas permeable (RGP) contact lenses can last even longer. Frequent or planned replacement contact lenses last one to several months. Disposable contacts last from one day (daily wear) to up to two weeks (extended wear).
Actual Contact Lenses Cost. Average Cost of Contact Lenses. The average cost of contact lenses can range from as low as $175 a year to $1,400 depending on your insurance, and what you and your doctor feel is the best lens for you: Monthly, 2-Week or Daily Disposal.