Introduction of Myopia
Myopia, commonly known as nearsightedness, is the most common eye problem in this industrial world, which is a big concern for people worldwide. The research shows one out of four Americans has myopia. The symptom is people can see clearly at a certain distance, but when the object is a little far away, the vision will become blurred. That is because the light from distant object can not focus on retina, but in front of the retina. One fact is though myopia is a worldwide eye disorder, we have to admit that people still don’t have much understanding of myopia, and till now no satisfying treatment has been developed.
Researches indicate that the modest overgrowth of the back part of the eye is the cause for myopia. And myopia can be transferred from one generation to the next, which means, if the father or mother has myopia, then their children are most likely to be nearsighted. One point we should know is myopia is opting to be worse in teenage, but it will become stable in adulthood.
Myopia can be classified into four degrees according to its severity, which is measured in diopter power. The more degrees myopia to be, the more serious the nearsightedness is. The four degrees are mild, moderate, common and extreme. For people with mild myopia, myopia usually does not influence their daily tasks, but when they see objects a little far away, the vision will become blurred. And for extreme myopia, which is in 6 or more diopters, people can see objects clearly only when they are very close to the eyes.
For the treatment of myopia, the most commonly used method is to wear glasses or contact lenses as most people do. The eyeglasses and contact lenses can help the light from distant objects to focus on retina. And the other way is to make Lasik surgery. Myopia is a growing eye disorder in the modern world. For one thing, it brings people with some troubles and inconveniences in their blurred vision; for another thing, it also drives the industries of glasses, contact lenses and eye surgeries.
Above all, we can see myopia is a common eye disorder in the modern world, but it is complex and difficult to solve. Besides, it also has some economic and social impact. So everyone should get to know some basic knowledge of myopia and try our best to take good care of our eyes.
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Myopia treatments
Also named nearsightedness, myopia is so common today that it is estimated to affect one-third of the population in the world. In contrast to hyperopia which deprive people from close vision, people with myopia can see up-close objects but can not manage distance things such as highway signs.
Similar with hyperopia, myopia also involves irregular eyeball shape. People with myopia have longer eyeballs than normal people, so that light rays are focused in front of the retina. Normal vision requires a light focus right on the retina.
Without proper correction, myopic people always squint to see distance objects and may suffer from headache and eye strain. Those wearing glasses or contact lenses with improper prescription are also bothered by these symptoms. As people age, myopia will stop progressing and become stable, although sometimes it performs myopic creep.
Whether you need full-time eyeglasses or contact lenses wearing depends on your degree of myopia. People with myopia have prescriptions with negative numbers, and a higher number represents a heavier myopia.
Refractive surgeries are becoming popular since they can reshape the cornea of myopic patients and eliminate the need for glasses. PRK and LASIK are two of the available refractive surgeries, both of which use an excimer laser. While a PRK just removes a layer of corneal tissue and flattens the cornea, a LASIK involves a flap cut through the top of the cornea.
For night wear, special contact lenses applying orthokeratology (ortho-k) can reshape the cornea over time and provide clear vision during daytime without lenses or glasses. As implantable lenses, phakic IOLs can deal with special situations that are beyond LASIK and PRK. These IOLs are permanently placed in the eye during the surgery, eliminating any maintenance.
There is also pathologic myopia, which is extremely severe and can not be corrected by any of the above treatments. This type of myopia occurs in children with extremely elongated eyeball by age 12. The situation will worsen as children age and unfortunately develop abnormal growth of new blood vessels. There was no effective treatment during a long period until the approval of drug Visudyne along with non-thermal laser application in 2001. This treatment named photodynamic therapy has been proved to be effective.