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).
Contact lenses are pieces of plastic or glass that rest on the eye, separated from the eye by a thin layer of tears. They are used to correct eye disorders. There are lots of kinds of glasses, but the most common kinds treat myopia, hyperopia, presbyopia, and/or astigmatism.