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).
DIA or Diameter: Every contact lens has a diameter. The diameter determines how much the lens will cover your cornea. Most contact lenses today come in just one diameter. In the picture above, the diameter is 14.5. Expiry Date: Indicates that the lenses in the box should not be used beyond the date of expiration or risk causing serious damage to your eyes. In the picture above, the expiry date is written in Month/Year format and is December 2017.