Hypoxia and hypercapnia
Hypoxia is a medical concept indicating a reduced supply of oxygen to the cornea. In addition, hypercapnia means an accumulation of carbon dioxide. In the past, contact lenses prevented the cornea from absorbing air gases, which was the cause of hypoxia and hypercapnia. Today, however, most of the contact lenses on the market are already capable of transmitting gases through the lens.