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).
optical: Custom-made eyewear and unopened contact lenses can be returned for a full refund within 24 hours of customer acceptance. Within 60 days of customer acceptance, we will exchange custom eyewear and unopened contact lenses for product of equal or lesser value. If you are unsatisfied with your purchase.