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).
In Europe and Asia, Daily Disposables are one of, if not the leading modality for contact lens wear, but in the US, daily disposables have captured only about 5% of the contact lens market. The primary reason is cost-to wear daily-disposable contact lenses full-time, you need about 360 pairs a year.oreover, daily-disposable contacts are generally considered the safest and healthiest type of contact lenses because the use of a fresh pair of lenses every day minimizes the chance for build-up of harmful pathogens on the lens surface. Each of the major US contact lens manufacturers offers a daily disposable contact.