Do contact lenses cause eye ulcers?

August 30, 2010 by  
Filed under VISION

I used to wear contact lenses but when I had my kids, it became too tedious to care for the lenses. I used to eyeglasses instead. They may not make me look great or fashionable but I find eyeglasses more practical. Little did I know that the decision to switch from contacts to eyeglasses may have some additional benefits.

The incidence of corneal ulcers may be more than previously thought – up to twice the previous estimates, according to a recent study. Cornea is the transparent white layer covering the front of the eye. Ulcers of the cornea can develop by viral or bacterial infections. It can start as a minor injury such as a small scratch on the cornea that can develop into open infected painful sores. In severe cases, the ulcers can lead to permanent eye damage and vision loss. The researchers attribute the increase in corneal ulcers to increased use of contact lenses.

According to researcher Dr. David Gritz of Montefiore Medical Center in New York:

“As new contact lens innovations become available, and people hear that they can wear these contact lenses for weeks or a month without taking them off, they do just that. They don’t realize the dramatic increase in risk it causes them. Our eyes do need breaks from contact lens wear.”

The research study looked at 1,093,210 patients treated in the Northern California Kaiser Permanente Health Care Program. Data on corneal ulcers, contact lens use, eye trauma or disease, and HIV status were collected. About 0.03% of these patients developed ulcers of the cornea during a 1-year period and more than half of these were contact lens users. The likelihood for corneal ulcers among those who use contact lenses is 9 times higher than those of non-users. Those who are HIV-positive have also a similar elevated risk. Young women seem to be especially susceptible to corneal ulcer – with double the risk compared to their male counterparts of similar age. The reason might be due to common use of cosmetic contact lenses by these women.

The fact that contact lenses are available over-the-counter or on the internet exacerbates the problem according to the researchers.

“People need to get properly fitted for contact lenses, and seek follow-up care by an eye care professional. Contact lenses can even act as a bandage over eye irritation, covering up symptoms. So people need to listen to what their eyes are telling them, and always have a good pair of glasses available as an alternative.”

Overnight lenses for young myopic eyes

November 3, 2009 by  
Filed under VISION

boy_in_safety_glassesI remember when about a year ago when our paediatrician referred us to an eye specialist to check my twin boys’ eyesight. I was praying silently “Please no eyeglasses…”

I mean, the likelihood that they would need glasses at an early age is quite high – it runs in my family. They were such active, sporty 5-year olds then; they are even more so now and are into soccer, gymnastics, inline skating, etc. I can’t imagine how they would manage to do all those active sports activities with glasses on. I remember how my brothers weren’t allowed to play basketball with their glasses on. That was so frustrating. Luckily, the eye doctor gave my kids a clean bill of health.

Some kids are not so lucky. There are many children out there with eyesight problems. The most common eye condition among children is nearsightedness (also known as shortsightedness or myopia).

Nearsightedness occurs when the physical length of the eye is greater than the optical length. For this reason, it often develops in the rapidly growing school-aged child or teenager, and progresses during the growth years, requiring frequent changes in glasses or contact lenses. It usually stops progressing as a person finishes growing in his or her early twenties.

A nearsighted person can see objects which are near very quickly whereas objects in the distance appear blurred.

Nearsightedness can be corrected by eyeglasses or contact lenses. The standard practice, however, is to take off the glasses or the lenses before going to sleep at night. A new type of contact lenses for children, however, requires that the children do wear them at night. This type of lenses is available for adults but only just now for children. So how do these lenses work?

It works  “by gently pressing on the cornea, reducing its curvature and thereby refocusing the light directly on to the retina. It also, in effect, shortens the eyeball. “

In the adult version, the effect of the lenses on reshaping the eyeball is temporary. The eye will eventually spring back to its original shape so that it is necessary to wear the lenses every night.

In the case of children, however, the lenses seem to have corrective effect that is long-lasting. The lenses slowed down the deterioration of the yes. In a clinical trial that involved more than 300 children, those who wore overnight lenses for a year did not have prescription change. Those who did not wear the lenses had increase in prescription indicating deterioration.

So why do the lenses work better for kids than for adults? Well, children’s eyes are still growing and are therefore more “malleable” than adult adults. The lenses work like a dental brace by restoring the eye to its original shape.


Photo credit: stock.xchng

An Introduction to Contact Lenses

May 21, 2008 by  
Filed under VISION

Today, contact lenses are as much for vision as they are for fashion. Giving wearers the ability to change eye color and design in literally the blink of an eye, contact lenses are no longer only for the nearsighted. But before you run out and purchase a pair sporting your favorite team’s emblem you need to carefully consider all that is involved in this seemingly harmless decision.

To wear or not to wear

Whether to wear contact lenses or not is a big decision and it’s one that should be well thought out. This type of cosmetic enhancement, while beneficial in most cases, can lead to the onset of serious eye and vision trouble if maintenance guidelines are not strictly adhered to. It’s not that contact lenses require a considerable or complicated amount of maintenance, but ensuring that the lenses are properly cleaned and stored does take a few minutes, every single time the lenses are worn.

A few minutes of work sounds like an acceptable trade-off for not having to deal with the awkwardness or cumbersome nature of wearing eyeglasses and it is. Contact lenses that fit right and that enhance a person’s vision can really change a person’s life for the better. The problem for contact lens wearers lies in the realization that cleaning and storage, those 2 critical contact lens maintenance issues, generally take place before going to bed, a time when contact lens wearers are usually most tired. For some, the tendency to ‘skip’ these steps in exchange for an earlier arrival into bed is just too good a temptation to pass up, and that decision is what leads to trouble.

Fortunately, those individuals have options. They can opt for disposable or extended wear contact lenses, both of which are designed to be maintenance-free. Wearers simply toss the lenses into the garbage and pop in a new pair when the recommended wearing period has lapsed.

Requirements for wearing contact lenses

There are only a few requirements for wearing contact lenses, the most important of which is the willingness to properly care for them. From there, a person must have a vision problem that contact lenses are able to correct. Even if being used for aesthetic purposes, individuals still need to be properly fitted which requires a prescription.

Tremendous improvements have been made to contact lenses since they first appeared on the market, and new technologies have expanded the number and type of vision problems that can benefit from corrective lenses. But still, not every vision problem can be corrected. That’s why the first step is to visit an optometrist or ophthalmologist to get a complete eye exam including a contact lens fitting.

That session is what will determine whether or not someone is a good candidate for contact lenses. Dry eye and age (maturity level) are some issues that might make a person a less viable candidate. The eye examination will also assist in determining the most beneficial type of lens so that a proper prescription can be written. With prescription in hand, the rest is fairly easy.

Correcting Astigmatism with Contact Lenses

May 15, 2008 by  
Filed under VISION

Astigmatism for a long time was an eye problem that could not be fully corrected with contact lenses. Mild astigmatism could be adequately improved with soft contact lenses, but there weren’t options for more severe cases. The eye problem itself results from a misshaped cornea – rather than being spherical like a ball, the cornea in people with astigmatism is oblong, shaped more like a football. Because of this shape, light rays can’t refract properly against the retina. Instead of focusing the rays on one spot, the odd shape causes light to refract in multiple locations on the retina, causing the blurred vision, regardless of distance, that is symptomatic of astigmatism.

Understanding toric contact lenses

The development of toric contact lenses opened up a whole new world of vision for people with astigmatism. Toric contact lenses don’t look any different than other soft or rigid gas permeable contact lenses, but in fact they are very different. The lenses consist of a number of different curvatures in various meridians or sections on the lens. Since astigmatism is a problem involving unbalanced meridian sections (due to the odd shape of the cornea) bringing the meridian sections back into balance is what helps produce clear vision.

Since the positioning of the various curvatures is key to improving vision, toric soft contact lenses cannot rotate – they must be held in a certain position in order to be effective. This is accomplished several ways. One way is to add weight to the bottom of the lens by building up or thickening that section. Another way is to make the top part of the lens lighter, by thinning this section.

Rigid gas permeable lenses are an option

Yet another way to correct astigmatism with contact lenses is to use rigid gas permeable lenses. These lenses are not as flimsy as soft lenses and that enables them to hold onto their shapes, even after blinking. Regular gas permeable lenses work effectively at correcting mild to moderate astigmatism, but in cases where the astigmatism is severe, it’s usually necessary to purchase gas permeable toric contact lenses. Toric lenses are custom shaped so that the inside of the lens more closely matches the shape of the astigmatism. Because of the customized fit, toric lenses remain in position and rotation isn’t an issue.

And because toric contact lenses involve customization, you’ll likely have to pay more for this type of contact lens. You might even find that your eye doctor charges more when fitting you for toric lenses because of the extra work involved in properly measuring each eye.

If you work with an eye doctor you trust, he or she will likely first try to prescribe regular contact lenses to treat your astigmatism. Again, mild and moderate astigmatism can usually be adequately corrected with standard lenses. Only when the astigmatism becomes severe is it necessary to resort to toric style contact lenses. When this happens, you’ll find that toric lenses are available as daily wear, extended wear, silicone hydrogel and disposable brands. They even come in an assortment of eye color options!

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NOTE: The contents in this blog are for informational purposes only, and should not be construed as medical advice, diagnosis, treatment or a substitute for professional care. Always seek the advice of your physician or other qualified health professional before making changes to any existing treatment or program. Some of the information presented in this blog may already be out of date.