Contact lenses have revolutionised the joy of vision in the past 70 years of Optometry. They work on the same light-bending principles as spectacles, except that they are “in contact” with the surface of your eye. More than 150 million people worldwide enjoy the convenience and versatility of contact lens wear.
The concept of contact lenses was born from ideas of Da Vinci and Decartes, bit it wasn’t until the 1800’s when Dr Fick designed the first contact lens. They were made of glass and nearly covered the entire eye. In the 1950’s smaller hard lenses were introduced. As technology and materials developed, the “soft” contact lens was launched in 1971.
As the eye is the only organ which gets oxygen directly from the air, it is very important that the contact lens allows enough oxygen transmission.
In 1998, silicone hydrogel material was introduced which significantly increased contact lens oxygen transmissibility that allows your eye to “breathe” making them much more comfortable and healthy to wear.
There are different types of contact lenses to suit different visual needs:
1) Hard lenses or scleral lenses for special eye conditions such as keratoconus
2) Orhthokeratology lenses that reshape your cornea overnight
3) Soft contact lenses for daily or monthly disposal:
a. Contact lenses for farsightedness, nearsightedness and astigmatism
b. Multifocal contact lenses
c. Color contact lenses
d. Transition contact lenses (react to UV light)
Most people can wear soft contact lenses comfortably and they offer wonderful benefits:
• Contact lenses allow for a wider field of vision and less peripheral distortions thus giving a more natural visual effect
• Higher refractive orders can be compensated without distortion effect or the unfortunate cosmetic appearance of “bottom-bottle glasses”
• They’re ideal for sporting activities
• They allow you to wear fashion branded sunglasses
• Hot or rainy weather conditions don’t affect your vision and they don’t get fogged up by masks like glasses do
Although contacts offer great advantages, there are also risks involved in wearing them. Contact lenses are classified as a medical device and require responsible maintenance. This is why it is not wise to order your contact lenses on-line or skip your yearly check-up with your Optometrist to ensure the health of your eye.
The main risks of contact lens wear are:
• Too little oxygen to the eye (ask your optometrist about the Dk/t value of your contact lenses).
• Overwearing your contact lenses – either not replacing them at the right time or keeping them in your eye for too long
• Accumulation of microbial and protein deposits risking eye infection
• Developing irritation or dry eye – especially with some medications (e.g. birth-control and anti-histamines)
Contact lens care is ESSENTIAL – but quite simple and hassle-free. Gone are the days when you needed many different products to clean your lenses. Modern multipurpose solutions provide an all-in-one disinfecting, rinsing, lubricating and storing solution.
Unfortunately, South Africa recently experienced a shortage of Contact lens solution due to the voluntary recall by Bausch &Lomb, affecting eight brands of contact lens solutions availability. This was due to a compliancy issue of one of the third parties in Italy responsible for sterilizing bottles and caps prior to manufacturing. Due to the shortage of these solutions, some people unknowingly used the hydrogen peroxide solutions which caused corneal burns. Please ask your Optometrist about the right solution for your contact lenses
The future of contact lenses is exciting and still developing. The introduction of “smart contact lenses” open possibilities that contact lenses can act as medical treatment devices:
• Johnson & Johnson is in the process of developing antihistamine-releasing contact lens. This lens could be used to decrease the symptoms of common allergic conjunctivitis.
• a new hydrogel contact lens material is in development which may be used to treat severe corneal injuries and auto-immune disease.
• Contact lenses that slowly deliver medication for Glaucoma and monitor intra-ocular pressure is almost ready for FDA approval.
• Lenses with biosensors that measure glucose levels from tears in and warn the individual when levels are too high
We hope you found this article interesting. If you are curious to know if you are a good contact lens candidate, feel free to contact us. We wish you great vision – the Optirite Team.
(Source: Optirite – The Islands)