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).
And they're made of materials that don't contain water (as soft contact lenses do), so protein and lipids from your tears do not adhere to GP lenses as readily as they do to soft lenses. With a little care, gas permeable contact lenses can last for years, as long as you don't require a prescription change.nd they're made of materials that don't contain water (as soft contact lenses do), so protein and lipids from your tears do not adhere to GP lenses as readily as they do to soft lenses. With a little care, gas permeable contact lenses can last for years, as long as you don't require a prescription change.