In fact, the problem of astigmatism is not complicated, but many friends don’t know what astigmatism refers to. Therefore, today I will share some knowledge about astigmatism with you. , I hope it can help everyone, let’s take a look at the analysis of this problem together!
Contents of this article
- What causes astigmatism
- What is astigmatism
- What is astigmatism
- Is there a degree of astigmatism
- What does eye astigmatism mean
- There are several types of astigmatism
1. What causes astigmatism
1. Astigmatism Definition: Astigmatism is called astigmatism in medical terms.
2. As the name suggests, it refers to the parallel light rays from the distance that, after entering the refractive system of the eyeball (mainly the cornea and crystalline lens), should originally be focused on a point and fall on the on the retina. If for some reason, it cannot be fully focused, but is scattered into different images, then what you see will become very \”chaotic\”, which is called random vision.
3. That’s because the eyeballs are not round enough. The reasons include uneven density or uneven surfaces of the omentum, crystalline lens, and cornea. Therefore, most people\’s eyeballs cannot be [just that round]. There is no astigmatism at all, usually only a minor difference.
4. According to research, astigmatism is often aggravated by poor eye posture. For example, lying down and reading a book, or even squinting or squinting when looking at things, will cause the eyelids to improperly compress the eyeballs and affect their normal development. Therefore, quitting bad habits is the best way to prevent astigmatism and myopia. These habits are often the cause of myopia, so some people think that myopia will cause astigmatism. In fact, the two have nothing to do with each other.
5. The so-called astigmatism refers to regular astigmatism. Most of this type of astigmatism is congenital and is mainly caused by abnormal corneal curvature. Among normal infants, the prevalence of this astigmatism is quite high, which may be related to the compression of the upper eyelids.
6. Sometimes called physiological astigmatism, the degree is very slight (25-50 degrees). This kind of astigmatism may decrease slightly with age, but the change will not be significant once it passes. .
7. Astigmatism caused by the lens is rare, and some are acquired astigmatism, such as long pinholes in the eyelids or milia, and long-term poor eye posture (such as squinting). Eyelids, rubbing eyes, lying down and reading, etc.), the pressure of the eyelids on the cornea will also change the curvature of the cornea and increase the degree of astigmatism. In addition, eye surgery (such as cataract and corneal surgery) may also change the degree and axis of astigmatism.
8. Irregular astigmatism means that the refractive power of each meridian of the eyeball is irregular within the same meridian. It is mainly caused by corneal diseases that cause unevenness on the cornea surface. , including keratitis, corneal ulcer, corneal scar, keratoconus, etc. Some early cataracts can also be caused by irregular refractive power inside the lens. Unlike regular astigmatism, where two main meridians can be found, irregular astigmatism cannot be corrected with cylindrical lenses.
2. What is astigmatism
1. Astigmatism ) is a refractive error, which means that the refractive power of the eyeball at different meridians is different. After the parallel light is refracted by the eye\’s refractive system, it cannot form a focus on the retina, but forms two focus lines, ultimately resulting in unclear vision on the retina. Image.
2. Astigmatism can be divided into regular astigmatism and irregular astigmatism. The former can be corrected with cylindrical spectacle lenses, while the other needs to be corrected with corneal contact lenses.
3. What is astigmatism
Astigmatism means: when parallel After the light enters the eye, due to the unequal refractive power of the eyeball at different meridians, it cannot focus on one point (focus) and cannot form a clear object image. This situation is called astigmatism.
The axis of astigmatism refers to the direction of astigmatism, usually in the range of 0-180 degrees. Without astigmatism, there is no axis.
A survey shows that 35% to 40% of Chinese myopic people have astigmatism above 75 degrees, but many people ignore the correction of astigmatism.
Mild astigmatism (below 75 degrees) generally has little impact on vision and is mainly related to eye fatigue.It depends on the degree of fatigue, and it will disappear automatically if you pay more attention to rest;
However, people with sensitive eyes may also be prone to eye discomfort, such as eye soreness, eye fatigue, and poor visual acuity. Blur, etc.;
If severe astigmatism is not corrected in time, in addition to the above symptoms, it will also cause amblyopia, distortion of vision, and blurred vision. Ghosting, like this. ?
2. Look at the picture below with one eye to see whether the depth and thickness of each line are even;
3. Yes: It means there is no astigmatism or the astigmatism has been corrected; No: It means there is astigmatism or the astigmatism has not been corrected;
Of course, this is only a preliminary measurement of whether there is astigmatism. Method; and to the specific degree, you must go to a professional eye hospital for comprehensive medical optometry! ?
1. Pay attention to your eyes, do not rub your eyes with your hands, and do not squint your eyes frequently. These habits can easily lead to the occurrence and growth of astigmatism;
2. Pay attention to the intensity of the light when reading or playing with mobile phones. It should not be too dark or too dazzling, let alone flickering;?
3. Pay attention to a reasonable diet and ensure sleep; eat more foods containing carotene and zinc to enhance the resistance and regulation of the eyes;
4. Those who need glasses should not check at will, but must go to a regular hospital for optometry; if there is astigmatism, the degree of astigmatism should be added in time to correct it;
In fact, astigmatism, like myopia, is a relatively common refractive error;
However, if there is astigmatism, It is absolutely necessary to carry out timely correction to prevent astigmatism from deepening and further affecting eye health!
4. Is there any degree of astigmatism
Astigmatism is divided into congenital forms of and acquired. , Astigmatism also has degrees. Generally, the physiological range is within 75 degrees. If it exceeds 75 degrees, myopic astigmatism or hyperopic astigmatism is generally considered. In most cases, it will affect the naked eye vision, and you need to wear astigmatism glasses. If you have myopia, Or hyperopia, which can be combined with astigmatism on the basis of myopia or hyperopia.
5. What does eye astigmatism mean
Eye astigmatism means the ability of the eyes to adjust Declines, unable to focus light onto the retina, resulting in blurred vision. The eyeball is usually spherical, but when the eyeball has astigmatism, it becomes irregular in shape, causing light to fail to fully focus on the retina, thus affecting the quality of vision.
6. There are several types of astigmatism
Astigmatism is divided into different types according to its shape. Different, divided into two types. The first type is regular astigmatism. Most of them are caused by the congenital irregular shape of the cornea. The degree is not too large and rarely exceeds 400 degrees. The second type is irregular astigmatism. Mainly secondary to various corneal diseases, irregular astigmatism can be corrected with contact lenses. If it is more serious, it may require refractive surgery.
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