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).
Generally, contact lens expiration dates are written in a yyyy/mm format. For example, an expiration date of 2015/12 means the lens should be considered safe for wear until the end of December 2015. Recommended For You. Wear contacts overnight, see clearly during the day with Paragon CRT. Hassle-free contact lens care for RGP and soft contact lenses from Lobob.