Many people who have myopia (near sighted-ness) often have signs and symtoms such as:
headaches
eyestrain
squinting
feel fatigued when driving or playing sports.
blurry distance vision
What i want to know is: why people who have myopia experience these symptons?? Nicole H gave you a very good answer. As to why people experience these symptoms, here is the answer:
Because the refractive power of an eye in myopia is stronger than necessary, light from distance objects focus in front of retina and images on the retina are blurry. These blurry distant images often pose difficulty in normal life (while driving, playing sports, interacting with people, etc.), so people start to squint.
Squinting is one mechanism that can "sharpen" distant vision to a degree. I'll try to explain how. Squinting reduces distance between light rays entering the eye from distant objects. Focus is still in front of retina, but the image formed on the retina is less blurry. Squinting also applies pressure on cornea and flatens it to a degree. This temporary flatening of cornea weakens refractive power of an eye and moves the focus of light toward retina and the result is better vision.
Squinting applies pressure on your eye entirely and since it happens all the time, it produces strain, fatigue and headaches. Squinting and strain in your eyes can also cause your eyes to elongate and myopia to progress further.
I also want to add that myopia is not incurable condition as is generally believed. Besides refractive surgery, there are eye exercises that can reduce myopia. I don't know how they work exactly, but I know for a fact that they work! It seems that through these exercises eyes somehow return to normal shape.
I suffered from myopia (-1.00 D) and was able to improve it completely with these exercises.
Best regards, Because the eye cannot focus properly putting a strain on the eye Myopia
Introduction to myopia
What causes myopia?
What are the symptoms of myopia?
How is myopia diagnosed?
How is myopia treated?
Introduction
Myopia (or nearsightedness) affects 20% to 30% of the population, but this eye disorder is easily corrected with eyeglasses, contact lenses or surgery.
People who have myopia or nearsightedness have difficulty seeing distant objects, but can see objects that are near clearly. For example, a person who is nearsighted may not be able to make out highway signs until they are just a few feet away.
What Causes Myopia?
People who are nearsighted have what is called a refractive error. This means that the light rays bend incorrectly into the eye to transmit images to the brain. In people with myopia, the eyeball is too long or the cornea has too much curvature, so the light entering the eye is not focused correctly. Light rays of images focus in front of the retina, the light-sensitive part of the eye, rather than directly on the retina, causing blurred vision.
Myopia runs in families and usually appears in childhood. Sometimes the condition plateaus, or sometimes it worsens with age.
What Are the Symptoms of Myopia?
People who are nearsighted often complain of headaches, eyestrain, squinting or fatigue when driving, playing sports, or looking more than a few feet away.
How Is Myopia Diagnosed?
Myopia can be easily diagnosed using standard eye exams given by an eye doctor.
How Is Myopia Treated?
Glasses, contact lenses, or refractive surgery can correct myopia.
With myopia, your prescription for glasses or contact lens is a negative number, such as -3.00. The higher the number, the stronger your lenses will be.
Refractive surgery can reduce or even eliminate your dependence on glasses or contact lenses. The most common procedures for myopia are performed with a laser, including:
Photorefractive keratectomy. Also called PRK , a laser is used to remove a layer of corneal tissue, which flattens the cornea and allows light rays to focus closer to or even on the retina.
Laser-assisted in situ keratomileusis. Commonly called LASIK , a laser is used to cut a flap through the top of the cornea, a laser removes some corneal tissue, then the flap is dropped back into place. LASIK is the most common surgery used to correct nearsightedness.
Corneal rings. Plastic corneal rings, called Intacs, are implanted into the eye to alter the shape of the cornea. One advantage of the rings is that they may be left in place permanently, may be removed in case of a problem, or adjusted should a prescription change be necessary.
Reviewed by the doctors at The Cleveland Clinic Cole Eye Institute.
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Edited by Charlotte E. Grayson, MD, WebMD, October 2004.
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From the Doctors at MedicineNet.com
LASIK Eye Surgery - Get information about LASIK, refractive surgery for vision correction (of astigmatism, nearsightedness, farsightedness), risk factors (dry eyes, high myopia or hyperopia) and benefits. Source:MedicineNet
Keratoplasty Eye Surgery (ALK) - Learn about Keratoplasty Eye Surgery (ALK) for nearsighted and farsighted vision problems. Source:WebMD Medical Reference from The Cleveland Clinic
Phakic Intraocular Lenses - Source:Government
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