The idea of lenses made from silicone hydrogel was very first proposed over 20 years back. Scientist companies have to date invested significant scholastic and monetary resources to attain the high efficiency soft lenses of today.
At the time of composing, silicone hydrogel lenses are offered in the USA from 4 makers: “Night & Day” and “O2OPTIX” from CIBA Vision, “Pure Vision” from Bausch & Lomb, and “Acuvue OASYS” and “Advance” from J&J Vision Care.
OXYGEN TRANSPORT
What’s so unique about silicone hydrogel as a lens product? Modern contact lens innovation is all to do with oxygen permability, which is determined utilizing the “Dk” index.
The Dk of standard, non-silicone based hydrogel lenses is straight associated to the quantity of water that the product can hold, given that oxygen liquifies into the water-component of the product and therefore diffuses through the lens. The Dk in reality increases logarithmically with increasing water material. Water itself has a Dk of just 80, hence positioning a ceiling on the Dk of convential products, and the initial soft contact lens product, polyHEMA, has a Dk of just around 10 (with a water material of about 38%).
With these lenses Dk increases considerably as the silicone material – not water material – of the lens boosts. The Dk worths of silicone hydrogel contact lenses are much greater than those of older soft lens products.
OVERSLEEPING CONTACT LENSES
According to market information from CIBA Vision, 84% of soft contact lens users periodically sleep with their lenses in, and one-third confess to doing this frequently. 25% of users of one to two-week non reusable lenses with low oxygen transmissibility sometimes or consistently oversleep their lenses overnight. And 72% of soft contact lens users stated they would choose to be enabled to use their lenses over night supplied it was safe.
Therefore the need for lenses with the capablities of silicone hydrogels is obviously really high with practically three-quarters of soft lens users wishing to have the ability to oversleep their lenses.
LENS HANDLING
Silicone hydrogel lenses are substantially more stiff than their standard equivalents, due to the existence of silicone. This increased rigidness does have some benefits, making the lenses significantly simpler to deal with and therefore the perfect option for users with a less fragile touch. There is a drawback to this nevertheless because the rigidness makes the lenses less vulnerable to embracing the shape of the eye so easily, leading to the possibility for a few of minimized convenience.
DECREASED DEPOSITIONS
Historically, the deposition of lipids and proteins has actually been an issue with contact lenses. The quantity of depositions is basically connected to the period of wear, the lens product and the tear structure of each private user. With conventional lenses, a regular replacement schedule significantly decreases the accumulation of hazardous deposits.
Silicone hydrogel contact lenses have actually been shown to provide significant advantages in the decrease of protein and lysozyme deposition. Integrated with the right replacement schedule and suitable care system, issues associated with protein deposition have actually ended up being practically a thing of the past.
DRY EYES
An issue often come across by users of standard soft contact lenses is among a sensation of pain and “grittiness” in the eyes towards completion of the day. It has actually been reported that after one week using silicone hydrogel lenses, the amount of routine soft lens users in a specific study hall who formerly suffered substantially from end-of-day dryness, was lowered considerably to just 13% of the sample.
WAY OF LIFE BENEFITS
Silicone hydrogel contact lenses likewise offer some advantages that traditional lenses do not. Constant wear contact lenses can be especially advantageous for usage by members of particular occupations, such as medical employees, cops, the militaries and firemens who regularly work long and unforeseeable hours.
An increasing numbers of contact lens users can now delight in active outside way of lives, delighting in pursuits such as outdoor camping and treking where it is frequently challenging to manage and sanitize the lenses with the proper level of health.
THE FUTURE FOR CONTACT LENSES
There is much proof to recommend that, owing to their considerable advantages over standard soft lenses, silicone hydrogel lenses will eventually, and faster instead of later on, displace other kinds of contact lens as the prefferred option for both over night and everyday wear for most of contact lens users. Silicone hydrogel lenses offer a much better physical efficiency, exceptional handling homes and higher convenience. They may be thought about as the perfect lens for basic function usage that exists today and are most likely to end up being the brand-new daily requirement.
With these lenses Dk increases substantially as the silicone material – not water material – of the lens boosts. The Dk worths of silicone hydrogel contact lenses are much greater than those of older soft lens products.
According to market information from CIBA Vision, 84% of soft contact lens users periodically sleep with their lenses in, and one-third confess to doing this routinely. And 72% of soft contact lens users stated they would choose to be enabled to use their lenses over night offered it was safe.
There is much proof to recommend that, owing to their considerable advantages over traditional soft lenses, silicone hydrogel lenses will eventually, and quicker rather than later on, displace other types of contact lens as the prefferred option for both over night and day-to-day wear for the bulk of contact lens users.