What You Need To Know About Silicone Hydrogel Lenses
The Development of Contact Lenses
Arguably the main preoccupation of contact lens developers over the years has been increasing oxygen permeability. If worn for an extended period of time, traditional contact lenses deprive the cornea of much-needed oxygen. Without adequate oxygen, the cornea dries out and can become inflamed, which is a condition known as keratitis. This can cause itchiness and pain, and in more severe cases, can impair vision and lead to long-term damage such as scarring. In the quest to find a longer lasting, comfortable contact lens, the ability to improve oxygen permeability is crucial. Thus, silicone hydrogel contact lenses have been a game-changer for all contact lens wearers.
Soft contact lenses were first created in the 1960s, after the development of ‘hydrophilic gels’ or hydrogels. Problems of keratitis became more widespread with the introduction of extended wear contact lenses in the 90s because more people were wearing contact lenses for longer periods of time. This resulted in many people getting infections.
The first silicone hydrogel contact lenses were introduced to the public in 1999. This amazing new technology allowed up to seven times more oxygen to reach the cornea compared to traditional hydrogel lenses, meaning that for the first time extended wear contact lenses did not lead to an increased health risk.
The higher permeability of silicone means that the oxygen permeability of silicone hydrogel lenses is not tied to the amount of water in the lens. For the wearer, this means increased comfort, and the ability to wear the lenses continuously for an extended period of time. Studies have also shown that any infections that do occur tend to be less severe than with traditional Hydrogel lenses.
Whilst they are not perfect, there is no denying that Silicone Hydrogel lenses represents a major step forward in contact lens technology, and it is no coincidence that the market has been heading in this direction for some years now. Whilst they may not be for everyone, almost any contact lens wearer is in a position to try them out, though we will always recommend that you consult your optician before switching your contact lenses. People who stand to benefit the most from Silicone Hydrogel contact lenses are those who tend to wear their lenses for more than twelve hours a day, particularly if they spend a lot of time in low humidity environments (offices with air-conditioning is one example of this). Patients with high prescriptions, or younger people who haven’t yet got the hang of their contact lens wear and maintenance routine, will also benefit, as will anyone who regularly experiences dryness, redness, or any other discomfort towards the end of a day wearing traditional contact lenses.
At Vision Direct, we stock a wide range of the leading brands of silicone hydrogel lenses, including Acuvue Oasys, PureVision 2 and Air Optix. Check out all the silicone hydrogel lenses available on our website here.