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).
If you wear contacts on a daily wear basis and clean and disinfect them after each use, expect your annual cost for contact lens care solutions to be roughly $150 to $200. So to determine your combined yearly contact lens costs for lenses and solutions, add $150 to $200 to the above totals.f you replace your contacts approximately every two weeks, this means you need about five boxes (30 lenses) per eye, or a total of 10 boxes per year. This comes to an annual contact lens cost of roughly $220 to $260 (lenses only).