Health News: Astigmatism refers to many scattered images produced by parallel light refracted by the refractive system of the eyeball, so it is called astigmatism.
Why is the focus scattered? That's because the eyeball is not round enough. Causes include uneven density or uneven surface of retina, lens and cornea. So most people's eyeballs are impossible [so round].
There is no astigmatism at all, usually only a slight difference. According to research, astigmatism is often aggravated by bad eye posture. For example, reading on your stomach, even squinting or squinting at things will cause the eyelids to oppress the eyeball inappropriately and affect its normal development. Therefore, getting rid of bad habits is the way to prevent astigmatism and myopia. And 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.
astigmatism
definition
Astigmatism is called number (confusion) in medicine. As the name implies, it refers to the distant parallel light, which should focus on one point and fall on the retina after entering the refractive system of the eyeball (mainly the cornea and lens). If for some reason, you can't focus completely, but become a different image, then what you see will become very, and it's called random viewing.
The cause of disease
Generally speaking, the so-called astigmatism refers to regular astigmatism. Most of this astigmatism is congenital, mainly caused by abnormal corneal curvature. In normal infants, the prevalence of this kind of astigmatism is quite high, which may be related to the oppression of the upper eyelid. Sometimes called physiological astigmatism, the degree is very slight (25-50 degrees). This kind of astigmatism may decrease slightly with the increase of age, and it will not change much after a period of time.
Astigmatism caused by lenses is relatively rare, and some of them are acquired astigmatism, such as long needle eyes or miliary swelling of eyelids, and poor posture with eyes for a long time (such as squinting, rubbing eyes, lying down reading, etc.). ), eyelid compression of cornea will also change corneal curvature and increase the degree of astigmatism. In addition, ophthalmic surgery (such as cataract and corneal surgery) may also change the degree and axis of astigmatism.
Irregular astigmatism refers to the irregular refractive power of each meridian of the eyeball on the same meridian, which is mainly caused by corneal diseases, including keratitis, corneal ulcer, corneal scar, keratoconus and so on. In the early stage of some cataracts, it can also cause irregular refractive power inside the lens. Irregular astigmatism can't find two principal meridians like regular astigmatism, and can't be corrected by cylindrical mirror.
symptom
Eyes are prone to fatigue and dryness.
What you see is distorted, the images overlap, and the far and near scenes are equally blurred.
Serious may lead to persistent headache, nausea and long-term tilt and other bad posture.
cheque
As for preschool children, if there is astigmatism above 200 degrees, it will make the image clear and fuzzy, and they have the habit of squinting with their heads tilted. Parents should take their children for eye examination as soon as possible to avoid missing the golden age of treatment (before the age of 6) and causing amblyopia. Children may not show visual impairment or abnormal eye habits, so parents should pay more attention to the development of their children's vision, do eye examinations regularly, find abnormal vision early and treat it early to avoid lifelong regrets of parents and children.
treat cordially
Mild astigmatism (within 50 degrees), the average person does not need to correct. However, people who are engaged in precision work or need to read fine print for a long time should consider wearing astigmatism glasses.
Moderate and high astigmatism, hyperopia astigmatism or myopia astigmatism are mostly corrected by wearing astigmatism glasses.
Corneal astigmatism, astigmatism contact lenses can be said to be the best, and even improve vision!
Corneal opacity or dehiscence caused by corneal injury requires corneal correction or astigmatism correction surgery.
Take care of yourself
Observe carefully, and if there is any problem, take it to the eye hospital for examination.
It is best to have the first full eye examination when you are 3-4 years old, and then have 1-2 eye examinations regularly in the following year.
Guide children to know those dangerous games and toys to reduce eye injuries.
Guide children to develop good hygiene habits, and don't touch eyes with hands or chemicals casually, so as to avoid eye diseases, such as eye diseases, and minimize going out.
When reading a book, the light should be sufficient, preferably from the left rear; Read correctly and keep a distance of 30 cm to 40 cm.
Don't read in the shaking car, and don't lie down and read.
When choosing reading materials, the font should be clear and not too small.
The height of the TV should be below the parallel line of the eyes. If you watch TV, it should be 5-7 times the diagonal of the TV picture.
I don't even look down on an hour, but I can rest for 5 minutes after 30 minutes.
Nutrition should be balanced.
Go to the suburbs to play more and see the green Yuan Ye in the distance.
People who need glasses should be examined by a doctor before wearing glasses.
Take the initiative to get in touch with the school and actively cooperate.