What are the outcomes of wearing contact lenses for long periods of time?
I have tried to alternate between wearing spectacles and contact lenses. However, I find it difficult to adapt to wearing specs as it gives me bad headaches, and hence am unable to get used to it. I wear contacts for about 16 hours a day. I would like to find out if there is any harm in wearing contact lenses for long periods of time?
Contact lenses are after all, a "foreign body". As such, prolonged wearing of contact lenses can indeed cause certain problems if proper care is not taken:
1) Most common problems are dry eyes and allergic conjunctivitis. These may make wearing contact lenses increasingly uncomfortable. In some cases, the allergic conjunctivitis manifest as chronic red and irritated eyes, with sudden sharp pain, fluctuation and blurring of vision.
2) Significant dry eyes can also lead to a higher risk of infection (cornea ulcers) as the dry spots act as entry ports for germs to gain access to the cornea. In mild cases, cornea ulcers can resolve with a course or two of antibiotic eyedrops. However, unfortunate cases may end up needing admission to hospital for intensive eyedrop treatment often every hour and through the night. Severe cases of infection can end up with cornea scars that reduce vision and exclude them from future LASIK surgeries. Rare cases may even require cornea transplant to clear the infection.
2) If the material of the contact lens is not sufficiently oxygen-permeable (not able to allow enough oxygen to reach the cornea) the cornea may develop small new blood vessels from its rim, which can become problematic when there is inflammation or infection.
To reduce your risk of contact-lens wear related problems, take care of the following:
1) Contact lens hygiene. Ensure strict hand hygiene when handling contact lenses. Wash and dry your hands. Tap water may harbour germs too! Choose daily disposable contact lenses if possible as they have less storage problems.
2) The better-tolerated contact lenses have higher oxygen permeability, which is calculated by a formula called DK/T. Try to ask about it.
3) Keep the eyes moist. Use lubricating eyedrops when necessary. There are labels that are compatible with contact lens wear. Look for them at the contact lens practitioners'.
4) Rest your eyes. Try to minimize hours of wear (I know this is tough...)
5) Get an eye check when things don't feel right. A proper examination at an eye doc's to make sure it is not anything serious can lead to earlier diagnosis and treatment, before big trouble begins.
6) Consider refractive surgery. If it is simply getting too much to cope with contact lenses and glasses, get a LASIK /ICL suitability test done. These can be highly satisfactory when done right.
All the best there. Cheerio!
Wearing contact lenses can be much better than glasses for 2 groups of people in particular-those with very high spectacle powers, and those with a big difference in spectacle power between the 2 eyes. In these groups of people, wearing glasses can cause an uneasy feeling or even sometimes headaches.
In the context of long duration contact lens wear each day, you need to differentiate between the different kinds of contact lenses.
Those with high spectacle powers (especially myopes-shortsighted people) and wear soft lenses for very prolonged periods each day run a higher risk of developing problems. These can range from dry eyes (since the thick contact lens material can act like a sponge and soak up some proportion of your tears, simplistically), to 'contact lens overwear' - a situation where people develop small 'spots' or erosions on the corneal surface due to a combination of dryness and lack of oxygen. This lack of oxygen can sometimes cause blood vessels to grow into the cornea.
This doesn't mean that every soft contact lens wearer will develop these problems. Still, it is important that these patients get regular eye check ups, so that if problems develop, they can be addressed at an early stage and alternative methods explored.
Besides soft lenses, there are also rigid gas permeable (RGP) contact lenses. These cause much less problems even with prolonged wearing, because firstly they tend not to dry the eyes out so much, but even more importantly they allow much better oxygen transmission through to the cornea. Being smaller than the cornea, these lenses do not cover the all important limbus, and so do not affect the corneal limbal stem cells. If you wear RGPs, and wear them for 16 hours/day, but have regular eye check ups and have been doing well so far, there may not be too much to worry about.
For those who are not familiar with RGPs, before you rush out and demand a pair from your friendly optometrist, bear in mind that it takes a while to get used to these lenses. At the beginning, many beginner wearers feel a constant foreign body sensation like an eyelash in the eye. A number of people give up before they actually get used to these lenses. But for those who can get used to them, they are a great option, especially for correcting high degrees of spectacle power.
Wearing contact lenses for prolonged periods of time can reduce the amount of oxygen that your eyes receive. This can lead to contact lens overwear and its many complications, such as dry eye and infection.
One common condition of contact lens overwear is giant papillary conjunctivitis. This occurs when your eyes produce an inflammatory response that appears as bumps underneath your lids. Not only does that cause discomfort to contact lens wearer, it may even lead to serious infection and contact lens intolerance.
It is important to regulate your wearing schedule so that your eyes are getting sufficient oxygen. I encourage you to attend regular eye examinations to ensure your eyes are in good health, especially if you do wear contact lenses for such long hours.
I am sorry to hear that your glasses are giving you headaches. Perhaps it is time to visit an optometrist for an updated pair of prescriptive glasses. Otherwise, you can always consider having laser vision correction as a way of achieving spectacles independence.
Dr David Chan