When wearing comfortable contact lenses, we sometimes forget that they are on our eyes. There are implications to wearing them for long periods of time. The cornea is the front-most part of the eye and is completely covered by soft contact lenses. Despite the cornea only being the thickness of a few strands of hair, it accounts for 2/3 of our focusing power, and is 300-600 times more sensitive than our skin. This extreme sensitivity serves as a protective mechanism, which is why we immediately blink when we feel the tiniest piece of dust come in contact with our eye. When wearing contact lenses, we increase the risk of damaging our cornea via two mechanisms:
Some of the most debilitating diseases of the eye include infections of the cornea. This is why eye care professionals pay particular attention to the health of the corneas of patients who wear contact lenses.
To minimize infection, daily disposable contact lenses are the safest option. When using these lenses, there is no need for storing or cleaning and minimal handling is required. Otherwise if wearing bi-weekly disposables, a very strict cleaning regime and timely disposal of lenses must be adhered to as recommended by your doctor of optometry.
All tissue in our body requires oxygen, and the transport mechanism of this essential molecule is blood. In order to see clearly, the cornea has to be transparent with no blood vessels in it. Oxygen is simply absorbed into the cornea from the atmosphere.
Now, if a piece of plastic is draped over the cornea this process can be disrupted. The material that comprises the contact lens must therefore allow oxygen to travel freely through it in order to maintain the health of the cornea. In general, silicone hydrogel lenses have the highest oxygen transmissibility but in consultation with your doctor of optometry you can make the best choice for your unique eyes.
Wearing contact lenses is quite different than wearing a pair of socks - rather they are medical devices that require attention from an eye care professional to prevent serious conditions. Whether you wear them for cosmetic, optical or medical reasons, the health of your eyes can be impacted by the improper usage of contact lenses. With proper wearing habits, ocular hygiene, and regular visits to your eye doctor, the risk of harming your eyes is essentially reduced to zero.