Silicone Hydrogel Contact Lenses
Silicone hydrogel contact lenses represent a breakthrough over traditional hydrogel soft contact lenses, because silicone lets so much oxygen (essential for a healthy cornea) pass through the lens. These lenses breathe six to seven times more oxygen than other lenses.
How Silicone Hydrogel Lenses Work
Traditional soft contact lenses are made from hydrogel polymers (soft, water-containing plastics). The plastic itself is not oxygen permeable, so the water performs the job of carrying oxygen through the lens to the eye. But water can carry only so much oxygen and the more water a lens contains, the greater its tendency to dehydrate after long periods of wear.
Silicone is oxygen permeable. So silicone hydrogel lenses use both their water and polymer content to transmit oxygen to the eye.
The benefits to wearers include comfort, enhanced optical health and convenience:
- Silicone hydrogel contact lenses contain less water than traditional hydrogel lenses. As a result, they are not as prone to dehydration while you are wearing them. For some people who wear their lenses for long days, this can mean better end-of-day comfort.
- Silicone hydrogels also have made 30-day contact lens wear sometimes called continuous wear, safe and available.
- Silcone hydrogel lenses are now made in daily disposable format (Acuvue Trueye), combining the convenience of a daily disposable lens with the benefits of silcon hydrogel material
- Silcon hydrogel lenses that correct astigmatism and in bifocal format are also available
