Astigmatism is a common vision defect most often caused by an irregularly shaped cornea, which blurs and distorts eyesight. Although some degree of astigmatism is found in most people, those with problematic, moderate or severe astigmatism should seek correction. Special prescription glasses and contact lenses can correct astigmatism. Laser or conventional surgery are now used, and new acrylic implants can be inserted to round out the cornea to eliminate astigmatism. However, these procedures are achieving varying degrees of success and their risks should be duly noted. Although astigmatism cannot be prevented, proper eye care and monitoring of your condition will help you see clear!
What is astigmatism?
Astigmatism is a common vision defect in which eyesight may be blurred at all distances. People with minor astigmatism may believe to have a clear vision, but find they are squinting from time to time or suffering from headaches, eye strain, fatigue and blurred vision depending on . An image viewed by persons with minor to moderate astigmatism may be blurry in some directions and clear in others (verticals, horizontals, obliques) and recognize better some letters shape (O vs T or X ). But people with severe or irregular astigmatism may see the world as a series of distorted images, as in a circus mirror.
If you have astigmatism, welcome to the club! The vast majority of the world’s population has some astigmatism. The tendency to have or develop astigmatism is inherited and always accompanies nearsightedness or farsightedness.Sotimes both. As time goes by, astigmatism may gradually become more pronounced.
Some say a light astigmatism oriented on vertical could be helpful for faster focus, particularly in our modern cities and spaces where horizontals and verticals are predominant.
Eyes and rugby balls
In astigmatic people, the cornea is not the usual half-sphere shape that it should be. In other words, instead of being shaped like half a soccer ball, the cornea is shaped more like half a rugby ball. When light rays hit the steep sides of the cornea, they are focused at two points instead of at one point on the retina (the nerve-rich lining inside the eye, where we “see”), producing blurred or distorted images.
Since minor astigmatism is considered normal, your eye doctor may tell you that no corrective eyewear or treatment is required for your particular condition. However, your vision may be corrected or improved upon with glasses or contact lenses at almost any degree of astigmatism if it is moderate, severe or causing difficulties.
Contact lenses can also help reduce the distortions caused by astigmatism, but they should be rigid gas-permeable (RGP) lenses. Soft contacts are not usually helpful unless they are special “toric” lenses, which are designed to correct the shape of the cornea. Toric lenses have an element that adds additional power called a cylinder and have greater light-bending power around one specific point. These lenses must be precisely designed to accommodate your needs.
Laser or conventional surgical procedures can be performed on healthy eyes to restore the spherical shape of the cornea and focus light precisely on the retina. For optimal results, more than one procedure may be necessary. If successful, these procedures may eliminate the need for eyewear. However, correction may not result in 20/20 (“perfect”) vision and prescriptive lenses may still be necessary. The long-term risks associated with these procedures should be noted. Risks may include overcorrection, undercorrection, sensitivity to glare, seeing halos around lights, poor night vision, daily shifts in the ability to focus and increased danger of corneal rupture or scarring, producing permanently clouded vision.
New acrylic lens implants may also be surgically inserted to correct mild astigmatism in some people. This procedure involves side effects similar to those associated with other laser and conventional procedures. In some cases, when side effects become pronounced, repeat surgery has to be performed to remove implants.
Since astigmatism cannot be prevented, standard eye care practices apply, as with any vision condition. If you suspect you may be suffering from astigmatism, see your eye doctor in order to correctly identify and address the cause of your problem so that it can be treated as soon as possible. As you age, you may find that your astigmatism gradually becomes more pronounced. Regular eye examinations will help determine if you need to change the strength of your lenses.
If you notice that your astigmatism is rapidly growing worse, see your eye doctor immediately. You may be experiencing the onset of a more serious eye disease known as keratoconus, which should be treated as soon as possible.
Parents and anyone who works with children should note that astigmatism may contribute to poor performance in school, and that routine eye tests conducted in schools may not detect defects like astigmatism. Make sure your children are thoroughly tested by a qualified eye doctor.
El Greco (1541–1614) was among the first portrait artists of his time to adopt the Mannerist style of painting, wherein the physical features of subjects are subtly elongated, changed and emphasized. For this reason, it was rumored that his sight was distorted by astigmatism. Whether or not this was true, some of his art did reflect with exaggeration the way in which an astigmatic person might view the world. Spaces are compressed, and colors and light interact in an unexpected and dramatic fashion. During his lifetime, El Greco used his subjective style to convey the powerful images of the Catholic church, which was trying to reform its practices and represent its doctrines in a new light in order to fight Protestantism. His painting was a bold, expressionistic emblem of his time. Today, El Greco is still lauded as a mystic and a prophet of modern art.
Astigmatism: an advantage in the urban jungle?
Research has shown that people with mild astigmatism tend to focus faster than others in environments that are dominated by horizontal and vertical lines. Therefore, some experts believe that these astigmatics might actually have an advantage in urban settings, where horizontal and vertical lines abound.
For more information
http://www.cvo-us.com/a.html
http://www.bluemarket.net/~eyedoc/text/astig.html
http://www.youreyesite.com/astigmatism.htm
http://www.adam.com/ency/article/0015.htm
http://www.adam.com/
http://www.bbc.co.uk/education/health/magazine/
http://www.cpmcnet.columbia.edu/texts/guide/
http://www.healthscout.com/cgi-bin/WebObjects/
http:/www.mayohealth.org/mayo/9906/htm/lazsurg.htm
http://www.mayohealth.org/mayo/9802/htm/
http://www.aoanet.org/cvc-astigmatism.html
