Development of refraction
Last reviewed: 23.04.2024
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Changes in the refraction of the eye continue throughout life. Depending on their age, they can be divided into seven periods:
- I - thoracic;
- II - infant;
- III - preschool;
- IV - school;
- V - active;
- VI - presbyopic;
- VII - involutionary.
When a person is born, the spread of the refraction of the eye is quite significant: from high myopia to hypermetropia of a high degree. The average refractive index of the newborn lies in the area of hypermetropia +2.5 ... +3.5 diopters. Most newborns have astigmatism, 1.5 dptr and more. During the first year of life in the process of active emmetropization, the spread of refractions sharply decreases - the refraction of far-sighted and myopic eyes shifts towards emmetropy, and astigmatism decreases. This process slows down a little during the 1-3 years, and at the end of the 3rd year of life, the majority of children develop refraction, close to emmetropia. In some children, the process of emmetropization does not reach its goal, they diagnose congenital myopia, hypermetropia more than 1,0-2,0 D, which are often accompanied by astigmatism and anisometropia. At the preschool age, refraction varies little, but some children may have early-acquired short-sightedness. The process of myopia is especially active at school age, when 25-40% of children develop short-sightedness (in some regions up to 90%).
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