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).
Related Questions. 1  Since getting contact lenses ten years ago, my eyesight has gone from -1.50 to -5.50. 2  I'm 17 and I seem to be getting more nearsighted. 3  I have the highest power on my glasses already. 4  I am 17 and I have -7.5 eyesight. 5  After 50 years of 20/20 vision, my eyesight has gone bad very quickly.