Silicone hydrogel contact lenses
A new generation of contact lens materials has been developed to improve on the performance of soft contact lenses and satisfy the health requirements of the eye.
Silicone hydrogels, first introduced in 1999, are highly permeable soft contact lens materials that allow more oxygen to reach the eye than conventional soft lens materials. Initially they were intended for long periods of uninterrupted use, including overnight wear, with minimal lens handling and cleaning. Today, these materials are most used for lenses that are worn on a daily basis and removed at night, and for daily disposable, single-use lenses too.
In fact, silicone hydrogels are now the most commonly prescribed soft lens materials in the UK and are more likely to be recommended for daily use than for extended (or 'continuous') wear. For people who need flexible wearing schedules or long hours of daily wear, silicone hydrogels may be particularly useful but they offer benefits for most soft contact lens wearers.
There are many different silicone hydrogel lenses available in the UK, not only to correct myopia (short-sightedness) and hyperopia (long-sightedness) but also for astigmatism (generally caused by an irregular cornea) and presbyopia (difficulty focusing on near objects with age). They come in an ever-increasing range of fittings, powers and designs. They're also used in some special medical applications and in custom-made lenses for unusual or complex prescriptions.
Silicone hydrogel lenses have been trialled by patients in studies carried out in many countries and found to have advantages over traditional soft lenses. Since the first generation of silicone hydrogels were launched, there have been further improvements to materials to improve performance and enhance comfort.
Not all silicone hydrogel lenses are the same and your eyecare practitioner will consider features other than oxygen performance when helping you choose the best lens for your eyes and vision. Your practitioner will also advise you which contact lens solutions work best with your lenses.
Some silicone hydrogel lenses are approved for up to 30 nights of continuous wear. However, your eyecare practitioner may suggest daily wear or a shorter wearing time with these lenses depending on your individual needs. Not everyone may be suitable for continuous wear and you should never sleep with your lenses on the eye unless specifically advised to by your practitioner. Remember that sleeping in contact lenses overnight carries a higher risk of contact lens-related infection, irrespective of lens type.
For more information on silicone hydrogel lenses, ask your eyecare practitioner.