The difference between nearsightedness and farsightedness.

Written by Li Zhen Dong
Ophthalmology
Updated on September 26, 2024
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Myopia is characterized by clear vision up close and blurred vision at a distance; hyperopia is characterized by clear vision at a distance and blurred vision up close. The main difference between myopia and hyperopia is the issue with the eye’s axial length. In an unaccommodated state, when parallel light rays enter the eye and focus in front of the retina, it is called myopia; when they focus behind the retina, it is called hyperopia. Myopic glasses are concave lenses, while hyperopic glasses are convex lenses. When myopia or hyperopia occurs, it is important to rest, reduce close-up activities, avoid eye fatigue, use eyes properly, eat a light diet, adjust your attitude, have regular check-ups, and pay attention to vision health.

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Written by Li Zhen Dong
Ophthalmology
39sec home-news-image

Is 1000-degree acquired myopia hereditary?

High myopia of 1000 degrees can also be inherited. The inheritance of myopia is mainly significant in cases of high myopia. If both parents have high myopia, the heritability is almost above 90%. If one parent has high myopia, the heritability is 45%. If neither parent is myopic, the heritability is nearly 5%. Myopia is primarily formed due to improper use of eyes rather than hereditary factors, which are relatively rare and generally only account for about 10% of myopia cases. Therefore, correct use of eyes is very important.

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Written by Wang Hui Zhen
Ophthalmology
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Can high myopia with bulging eyes be corrected?

High myopia with bulging eyes is caused by the elongation of the eye axis, which is irreversible. Myopia is when parallel light rays entering the eye are focused in front of the retina, after passing through the eye's refractive system, and thus cannot form a clear image on the retina. Myopia can be classified into low, moderate, and high degrees, with high myopia defined as 600 degrees or more. Once myopia progresses to true myopia, it is incurable, and one can only correct or control its progression. Before the age of 18, myopia can only be corrected and controlled by wearing frame glasses or orthokeratology lenses; after the age of 18, elective surgeries like myopic correction surgery or artificial lens implantation are also available options for correcting myopia.

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Written by Peng Xi Feng
Ophthalmology
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The main cause of myopia formation

Myopia is primarily caused by the focusing system of the eyeball focusing parallel light rays in front of the retina when our eyes are in a relaxed adjustment state. The far point of a myopic eye is at a certain point in front of the eye. The occurrence of myopia is influenced by a combination of factors including genetics and environment, and the incidence is still being explored. Based on the refractive components, myopia can be classified into refractive myopia and axial myopia. According to the degree of myopia, it can be classified into mild myopia (below 300 degrees), moderate myopia (300 to 600 degrees), and high myopia (above 600 degrees). The clinical manifestations of myopia include blurry distance vision but good near vision, often with fluctuating distance vision where squinting is needed to see clearly at a distance.

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Written by Zhou Qing
Ophthalmology
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How is the surgery for nearsightedness?

The choice and design of myopia surgery methods need to be comprehensively considered based on factors such as the patient's preoperative examination results and postoperative vision requirements. Generally, patients can choose laser myopia surgery. If high visual acuity is needed due to study or work, or if there is high physical activity after surgery, it is recommended to choose a safer surgical option. This is because minimally invasive technology causes less trauma to the corneal nerves, which can more effectively improve postoperative night vision, greatly enhance visual quality, and better stabilize postoperative vision.

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Written by Zheng Xin
Ophthalmology
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What should I do if nearsightedness is inherited by my child?

Not all myopia is hereditary, but high myopia does have a genetic component. The occurrence of myopia is mainly related to genetic and environmental factors. If there are children in the family with a history of high myopia, they should develop good eye habits from a young age, or undergo genetic testing for high myopia. If myopia occurs, it can be corrected by wearing glasses, or by refractive surgery after reaching adulthood.