Optometry Articles

Myopia-Nearsightedness

Nearsightedness, or myopia, as it is medically termed, is a vision condition in which people can see close objects clearly, but objects farther away appear blurred. People with myopia can have difficulty clearly seeing a movie or TV screen, a whiteboard in school or while driving.

Myopia (nearsightedness) is a refractive error. Refractive error is when the eye does not bend (refract) light properly. Light does not focus correctly so images are not clear. In myopia, close objects look clear but distant objects appear blurred. Myopia is a common condition . It is an eye focusing disorder, not an eye disease.

The eye's tear film, cornea and lens bend light so it focuses on the retina. The retina receives the picture formed by these light rays. It sends the picture to the brain through the optic nerve. Myopia occurs if the eyeball is too long or the cornea (the clear front cover of the eye) is too curved. As a result, light rays focus in front of the retina instead of on it. In this case, you see near objects clearly, but distant objects will appear blurred.

While the exact cause of myopia is unknown, there is significant evidence that many people inherit myopia, or at least the tendency to develop myopia. If one or both parents are nearsighted, there is an increased chance their children will be nearsighted.

Even though the tendency to develop myopia may be inherited, its actual development may be affected by how a person uses his or her eyes. Individuals who spend considerable time reading, working at a computer, or doing other intense close visual work may be more likely to develop myopia.

Generally, myopia first occurs in school-age children. Because the eye continues to grow during childhood, it typically progresses until about age 20. Myopia is often discovered in children when they are between ages 8 and 12 years old. During the teenage years, when the body grows rapidly, myopia may become worse. However, myopia may also develop in adults due to visual stress or health conditions such as diabetes.

If the myopia is mild, ophthalmologists call this low myopia. They call severe myopia high myopia. High myopia will usually stabilize between the ages of 20-30 years old. Usually, you can correct high myopia with glasses or contact lenses. Sometimes, refractive surgery can correct high myopia.

Myopia may also occur due to environmental factors or other health problems:

1、Some people may experience blurred distance vision only at night. With "night myopia," low light makes it difficult for the eyes to focus properly. Or the increased pupil size during dark conditions allows more peripheral, unfocused light rays to enter the eye.

2、People who do an excessive amount of near-vision work may experience a false or "pseudo" myopia. Their blurred distance vision is caused by overuse of the eyes' focusing mechanism. After long periods of near work, their eyes are unable to refocus to see clearly in the distance. Clear distance vision usually returns after resting the eyes. However, constant visual stress may lead to a permanent reduction in distance vision over time.

3、Symptoms of myopia may also be a sign of variations in blood sugar levels in people with diabetes or may be an early indication of a developing cataract.

A doctor of optometry can determine the cause of the vision problems through a comprehensive eye exam.

People with myopia have a higher risk of developing a detached retina. Ask your ophthalmologist to discuss the warning signs of retinal detachment with you. See your ophthalmologist regularly to watch for changes in the retina that might lead to retinal detachment. A surgery can usually repair the retina if you discover the detachment early enough.

People with high myopia may also have a higher risk of developing glaucoma and cataracts.

Myopia(Nearsightedness) Symptoms: Some of the signs and symptoms of myopia include: eyestrain,headaches,squinting to see properly,and difficulty seeing objects far away. These symptoms may become more obvious when children are between ages 8 and 12 years old.