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).
This part of the process is extremely important â which is why a new contact lens fitting and evaluation often require an hour or so, in order to obtain the best results.â. Step 3. A follow-up visit to the eye doctor is key, and is usually planned one or two weeks after the original fitting.