Hypoxia and contact lenses
Hypoxia occurs when the cornea does not get enough oxygen. It is the most common complication of contact lens wear, especially extended-wear lenses.
The cornea has no blood supply of its own, so it gets oxygen only from tears and directly from the atmosphere. A contact lens reduces the oxygen supply to the cornea, making the cornea swell. Wearing contacts overnight further decreases the amount of oxygen that gets to the cornea.
Gas-permeable hard contact lenses have almost eliminated some once-common problems, such as over wearing syndrome and corneal clouding; still-common problems include hazy vision caused by mild corneal swelling (edema) or warping. Over time, corneal hypoxia may cause serious problems with the cornea.
| Author: | Robin Parks, MS | Last Updated: August 22, 2007 |
| Medical Review: | Kathleen Romito, MD - Family Medicine Carol L. Karp, MD - Ophthalmology Andrew Swan, MD, CCFP, FCFP - Family Medicine | |
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