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).
First of all this is wrong if you ask and already are a contact lenses user. Watch this picture, this is from the box of the brand Iâve been using for 2+ years: Itâs in spanish but as every LEGAL contact lenses box, there MUST BE instructions behind the box and specification of use time. The box you see above clearly says: âFor using 7 days and 6 nights or 15 days if you take them off when sleepingâ. This is specifically from the brand Iâm using but according to the one you use, there should be specifications of HOW LONG you can wear them, if you can sleep with them, etc.