Why does the eye develop hyperopia? How does hyperopia form? What causes hyperopia? When the ciliary muscle is in an unregulated state, the eye with parallel light forming focus behind the retina is called hyperopia. There are three main causes of hyperopia
(1) Axial hyperopia: it is the most common in hyperopia eyes, that is, the anterior and posterior axis of the eye is shorter than that of the emmetropia eye, and it is also a common type of refractive abnormality. At birth, the average axial length of human eyes is about 17.3mm, which is in the hyperopia state of + 2.50 to + 3.00d. It can be said that the hyperopia of infants is physiological.
With the development, the axis of the eye also grows slowly. However, at the age of 5, 90% of the children are in the state of hyperopia, and at the age of 16, it is reduced to 50%. However, due to the low degree, they are in the range of adjustment and generally do not feel it. Some people in the eye development process, due to genetic, environmental and other factors, eye stop development, eye axis can not reach the normal eye length, the formation of axial hyperopia. Most of the hyperopia in clinic is within + 6D, but there are also hyperopia eyes with high degree, some even as high as + 24D.
(2) Curvature hyperopia: it is formed by the small surface curvature of any refractive body in the ocular refractive system. It is mostly caused by congenital factors, such as congenital flat lens, congenital flat angle membrane, etc.; it is also caused by corneal trauma. In recent years, due to the popularity of refractive corneal surgery, hyperopia caused by overcorrection of myopia surgery is gradually increasing, which should be paid attention to. However, in the early stage after PRK, because the corneal epithelium has not been completely repaired, hyperopia often appears in stages. It should be explained to patients in advance, so as not to cause unnecessary misunderstanding.
(3) Refractive rate hyperopia: it is caused by the decrease of refractive index of aqueous humor and lens and the increase of refractive index of vitreous body. This kind of reason is rare. It is mainly seen in the elderly and patients with diabetes. Some lens dislocation can also lead to hyperopia. In addition, ocular wall and intraocular tumor, omental edema, orbital inflammatory mass, and even omental dissection can cause pathological hyperopia.
The clinical manifestations of hyperopia are as follows: high hyperopia in childhood can lead to amblyopia and strabismus, which should be paid great attention to; moderate hyperopia is easy to be tired of learning and inattention due to near visual discomfort, which is often mistaken for naughty and ignored examination. Young people need to use the power of regulation to move the focus behind the retina to the retina, so the eyes are often in a state of regulation, which is more prone to eye fatigue than myopia and emmetropia. For example, writing, reading, watching TV and so on, when they are close for a long time, they will feel heavy eyelids, dry eyes, sore eyes, swelling, pain and so on, and then blurred vision, dizziness, swelling, headache and so on. In the middle and old age, due to the lack of regulation, the expression of "old flower" is in advance. With the gradual loss of elasticity of the crystal, it is difficult to see clearly.
After reading the above content, we should have some understanding of why the eyes are hyperopia? How the hyperopia eyes are formed. Why the eyes are hyperopia? How the hyperopia eyes are formed? Today we will introduce here. More words about eye health will continue to be introduced in the following articles. Welcome to check. Wish you a happy life!