Many children were encountered in the outpatient clinic, because the kindergarten physical examination found that there was astigmatism, and they were brought by their parents for examination. There are also many parents who ask the doctor, my baby has astigmatism, do I need to wear glasses? The doctor's answer is: not necessarily, it must be analyzed on a case-by-case basis!
First of all, we need to clarify a concept, astigmatism is not a disease, most people have astigmatism. The study found that about 60% of adults have astigmatism below 25 degrees, and clinical astigmatism that does not affect vision at 50 and below 50 degrees is generally called "physiological astigmatism". So if the doctor says you don't have astigmatism, either your astigmatism is small and doesn't affect your vision, which can be ignored.
What exactly is astigmatism?
Under normal circumstances, the external light is converged on the retina through the refractive system, and we can clearly see things. People who are nearsighted are because light is concentrated in front of the retina, and people who are farsighted are light that converges behind the retina.
But our human eye refractive system is not a standard circle, but a similar oval-like form, so the external light through the eye refractive system converged into the eye, in the position will produce a certain difference before and after, the position difference of this light convergence point will form the degree of astigmatism, and the refractive system The highest or lowest refractive force is located in the dimension is the axial direction of astigmatism.
The effect of astigmatism on vision mainly depends on two aspects: the level of astigmatism and the position of astigmatism, that is, the axial direction of astigmatism.
What are the effects of too much astigmatism?
1. Affects the development of the visual cortex and causes amblyopia. Studies have found that amblyopsis and astigmatism in the subordination and inverse scale at 150 degrees and above, oblique astigmatism at 100 degrees and above have the risk of causing amblyopia, and as the number of degrees increases, the probability of amblyopia will be higher. If the astigmatism is above 250 degrees, the probability of causing amblyopia is very high, whether it is a shun, aberration or oblique axis.
2. Affects naked eye vision. The essence of astigmatism is also a refractive error, so when the astigmatism reaches a certain degree, it will have an impact on vision. However, the effect of astigmatism on vision is not only in the degree, but also has a great relationship with the axial direction.
3. Affect binocular visual function. We humans are binocular visual animals, so in infancy, in addition to vision, the development of tertiary visual function in both eyes is also important. The development of normal binocular tertiary visual function requires the following basic conditions: the clarity, size, and color proximity of the images seen by the binocular eyes. If the amount of astigmatism in the two eyes is largely different, or there is a large difference in axial direction, it will lead to deviations in the clarity of the images seen by the two eyes, and it will be difficult for our brains to fuse. Eventually, monocular suppression or even strabismus may occur.
4. Visual fatigue, headache, eye discomfort, etc. The study found that in the population of eye fatigue and headache, the proportion of patients with astigmatism is very high, and scientists speculate that this may also have a lot to do with the special blurring of vision caused by astigmatism, and some people have found that some children will have crooked heads and squinting eyes because of astigmatism.
Does the child need to intervene immediately when he finds astigmatism?
Astigmatism, like myopia, cannot be cured except for refractive surgery correction in adulthood. At present, the conventional medical intervention to deal with excessive astigmatism is to wear glasses or contact lenses of the cornea, the purpose of which is also very simple, that is, to make us see more clearly.
Therefore, one of the simplest and most basic conditions for judging whether a child needs to wear astigmatism glasses is to see whether astigmatism affects naked eye vision, whether there is a risk of causing amblyopia, and whether it causes abnormal development of binocular visual function. Therefore, when considering whether to give children glasses, you can not simply pass the degree of one-size-fits-all, but also consider the child's naked eye vision, binocular visual function and other humanistic psychological factors.
If the astigmatism is below 100 degrees, and the axial position of the eyes is symmetrical, there is no need to worry too much, and there is generally no problem. Astigmatism in 100 ~ 150 degrees, you must first look at the vision of the situation, if the vision of both eyes are qualified and symmetrical, the child does not tilt the head, squint the vision, etc., and the binocular visual function is well developed, it can also be temporarily unspectacled, but must be 3 months to half a year follow-up observation. When the astigmatism is above 150 degrees, due to the risk of amblyopia, the probability of dispensing glasses will be greatly increased, but it is still necessary to take it to the hospital for evaluation and examination.
Therefore, if the child is found to have astigmatism, take it to a formal professional ophthalmological medical institution for relevant examinations for the first time, and further treatment according to the opinions of professional doctors, and avoid excessive intervention because of anxiety.