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Corrective Lenses Today many people suffer from eye illnesses. And many of those people choose to wear corrective lenses, but they dont not much about them. When we use things, we often dont realize how important they are, what meaning they possess. So what are corrective lenses? How do they work?
To understand that we have to know how a human eye works. The work of a human eye is based on a principle similar to that of a camera. An eye has a natural lens through which the light goes and focuses on the retina, where the image is created. The retina is a thin layer of cells located at the back of an eye.
The lens bends the light when it enters the eye. It changes into a more or less curved shape depending on the distance between the object we want to focus on and the eye itself. The clear covering on the front of an eye is the cornea. The cornea helps in focusing the light onto the retina. If these elements work properly we have a clear image on the retina and have no problems with vision. Eye problems occur when the light entering the eye is not properly focused onto the retina.
In this case, corrective lenses can help. They help to focus the light on the retina. The retina also may not have a clear image because of the cornea distorting the light entering the eye this disorder is called astigmatism. Corrective lenses are also helpful in this situation. One more illness is presbyopia.
It occurs when the eyes ability to adjust the focus on the distance between the person and the object is lost. Simple magnifying lenses easily fix this disorder. As we see corrective lenses can appear very helpful, but unfortunately, they cannot solve all serious vision problems. Here are some of the illnesses that lenses cannot help: cataracts, albinism, optic nerve damage, macular degeneration, retinitis pigmentosa, nystagmus, retinopathy of prematurity (ROP), Ushers syndrome etc. Corrective lenses are not helpful to people who have a retina disorder due to diabetes.
We can prevent developing some of the illnesses by simple attention to our children. Infants and toddlers should be screened for most common childhood problems, such as strabismus and amblyopia. Early detection of these illnesses is extremely important to your childs eyesight. When undetected or left untreated, amblyopia can result in permanent vision loss, said Ronald Keep, M. D. , UI professor of ophthalmology and visual sciences.
Vision testing is recommended for all children starting at around age of 3. Some warning signs that you may notice if your child has vision problems are: wandering or crossed eyes, a disinterest in reading or viewing distant objects, squinting or turning the head in an unusual method while watching TV. Another danger to childrens eyes is accidental injury. So it is recommended to wear protective eyewear during risky activities. So eye care and protection, early detection and treatment of eye disorders can prevent many problems. Speaking of the young adult and middle-aged groups, there are people at risk for eye diseases.
African Americans over age 40 (glaucoma), people with diabetes (diabetic retinopathy) and those with a family history of eye problems should all visit an eye specialist and check their eyes condition. These individuals are more likely to have eye diseases and should have a complete eye exam at least once between ages 20 and 29, twice between ages 30 and 39, and every two-four years between ages 40 and 65 to detect the disorder in time. But what about those who do not correspond to the descriptions mentioned above and they still have eye problems? According to statistics, 54 % of Americans between the ages of 18 and 29 wear corrective lenses. It is a high percent as for the young people who are supposed to be strong and healthy. So why is it so?
The answer involves evolution, genes and the environment. Have you ever asked yourself: Why do I have eyes? What is eyes purpose? The answer to this question is very important. Our eyes were first evolved for hunting and gathering.
When our ancestors were hunting, they had to see animals and birds clearly. So years ago we mostly focused our eyes on distant objects, and on closer objects for gathering. But in the modern world an average human being has a new necessity reading. Reading is a really close work and it demands a continuous eyes strain. our eyes have not evolved commensurately, says Robert Elsa's of Davis Vision. Our eyes may even be changing in the wrong direction.
Myopia, for example, may result from an interaction between genes and the increasing close work that is so typical of society today. Theres a strong evidence for an association between near work and myopia, says Katrina Schmid, School of Optometry, Queensland University of Technology, Brisbane, Australia It is always more difficult to keep yourself healthy in old age. In fact, presbyopia, which is a condition that causes a loss in the flexibility of the natural lens inside the eye (the lens becomes too rigid to change into a more curved shape to see near objects), affects 93 % of the worlds population over the age of 45. Ninety percent of Americans wear corrective lenses after age 49. Another factor that influences our eyes is computer work. Most computer users have Computer Vision Syndrome (CVS).
In fact, 50 % - 90 % of computer users experience the symptoms of this disorder. Fortunately, these symptoms and problems can usually be alleviated by good eye care and / or by changes in the work environment. Computer users should be tested for eyesight, tear film stability, eye teaming and eye focusing. Signs that may indicate a Computer Vision Syndrome are: eyes burn or red after using computer; blurry vision at any distance after computer use; double vision, or the words run together; headaches with near work; vision is worse or neck ache at the end of the day.
Again, about the corrective lenses what are the advantages of wearing them? Many wearers do not like the appearance of eyeglasses or even like their eyes better when wearing lenses. There is no obstruction from eyeglass frames. Corrective lenses provide much better peripheral vision.
Another advantages no fogging up in warm rooms or splattering during rain showers. Lenses dont get in the way during sports and similar physical activities. Although there are a bit of disadvantages: Contact lenses require getting used to. It needs about a week for new soft lens wearers, but a somewhat longer period for those who use rigid lenses. Almost all lenses require regular cleaning and disinfection, but it is more that some people want to undertake.
And one more disadvantage some types of lenses increase your eyes sensitivity to the light. However, if you do your best to take care of your eyes and visit a specialist regularly, you probably will not even need to decide whether to wear glasses or corrective lenses. Bibliography: web USA Today, Gannett Co. Inc. , 07 / 18 / 2001 -Updated 07: 41 PMET, visited 10 / 12 / 2004 web University of Iowa Health Care, University of Iowa, Updated Wed Aug 6 15: 23: 15 2003, visited 10 / 12 / 2004 web University of Iowa Health Care, University of Iowa, Updated Fri May 23 12: 50: 37 2003, visited 10 / 12 / 2004.
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