What is the vision standard for children?_Industry News_
Children's vision is a process of continuous development, and vision is different at each stage. People's normal vision is 1.5-2.0. Because children are still growing and their eyeballs are also developing, there are changes in their vision. So what is the standard for children's vision, let's take a look at it together. Overview To determine whether a child’s vision is normally developed, we must first know the range of normal vision at different ages. According to the literature reports published by applying different methods (OKN, VEP, PL) to measure the visual acuity of infants and young children, most experts believe that the visual acuity of the newborn and one month after birth is light perception ~ manual operation in front of the eyes, and the visual acuity of 2 months is manual operation in front of the eyes ～0.01, 3 months visual acuity is 0.01～0.02, 4 months visual acuity is 0.02～0.05, 6 months visual acuity is 0.06～0.08, 8 months is 0.1, 1 year is 0.2～0.3, 2 years is 0.5～0.6, 3 It may reach around 1.0 at the age of. But at the same time, studies have pointed out that there are differences in visual development. Some people are earlier and some are later, but most scholars believe that normal adult vision can develop after 6 years old (or even 10 years old). The visual function of children is not mature before the age of 6, and the visual function is not sound or consolidated. This is a plastic and changeable stage. All factors that hinder visual stimulation can block the development of visual function and stop the development of visual function. , Developmental delay, underdevelopment or dysfunction, resulting in amblyopia. Under normal circumstances, the child’s visual acuity at 1 year old is 0.2, and the visual acuity increases by about 0.2 for every 1 year old. The child’s visual acuity at 5 years old should be 1.0 or more, after 8 years old it should be around 2.0, and it should be saturated after 14 years old. Vision may reach about 3.0. 1.0 is only the minimum standard for normal vision, and 1.5 is not the best vision. The product of age multiplied by 0.2 is used as the reference standard for preschool children's vision. Since this reference standard is based on age and eye development, it is also scientific and reasonable, and it can be said to be suitable for everyone. Vision development status is 1 to 3 years old. Eye and vision development starts from 1 year old. Children especially like to use eyes to guide hand activities. They like to be in touch with new things. As a result, the coordination ability between eyes and hands grows rapidly. Visual recognition ability is in This stage has also been greatly improved. The standard of vision development for children aged 1 to 3 years can reach between 0.1 and 0.6. Generally, it is 0.4 at 2 years old. It can already distinguish the distance of things, and the line of sight can keep up with fast-moving things and see clearly. At the age of 3, it is 0.6. He has sharper vision and likes to observe. He uses his eyes to guide his hands to touch new things. The eye-hand coordination is more flexible. The establishment of stereo vision is almost complete. 4 to 6 years old, eyes and vision development of 4 to 6 years old children's vision has gradually matured, and the clarity of vision has increased, reaching 1.0 at the age of 6, basically reaching the level of an adult. If the child's vision is abnormal at this stage, there are obvious signs. Like to watch TV up close, like to squint or tilt your head to see things, like to rub your eyes, or particularly not interested in visual activities, these should all be taken seriously. The myopia problem has also emerged at this time. When a child is watching TV or reading a book at close range, and often complains that he can’t see clearly and is easy to knock down something, it may be an important sign of myopia, and he needs to be checked in time and continue to undergo various corrections. treat. Characteristics of children's vision development The appearance of the eyeballs of newborns is almost round, and the adjustment ability of the eyeball lens and ciliary muscles is poor. After the parallel light passes through the refractive system, the image falls behind the retina, which is better for hyperopia. After about 6 years of age, children's vision development tends to be perfect, and gradually develop from hyperopia to emmetropia. This process is called the emmetropization process of the eye. When the distance vision (at a distance of 5 meters) in a single eye reaches 1.0 (logarithmic visual acuity table 5.0), the eye is emmetropia. As the age increases, the contractility of the lens and ciliary muscles weaken, so the ability to adjust to light decreases, resulting in unclear vision near objects. This phenomenon is called presbyopia or presbyopia. Children’s visual acuity and refractive power has been studied by a large number of clinical data from many authoritative hospitals at home and abroad, and the physiological values u200bu200bof children’s visual acuity and refractive power are as follows: children between 2 and 3 years old, with a visual acuity of 0.5 or above, and a diopter between 100 degrees and 250 degrees for hyperopia Children 3 to 4 years old, with a visual acuity of 0.7 or above, with a diopter between 100 degrees and 225 degrees for hyperopia, children from 4 to 5 years old, with a visual acuity of 0.8 or above, with a diopter ranging from 75 degrees to 200 degrees for hyperopia, and children over 5 years old , The vision is 1.0 or above, the refractive power is between 75 degrees and 175 degrees for hyperopia, children over 6 years old, the visual acuity is 1.0 or above, and the refractive power is between 50 degrees and 150 degrees for hyperopia, if the visual acuity of children over 10 years old is only 1.0 , We should start looking for measures to prevent and control vision loss. It is normal to exceed 1.0 at this age. Otherwise, after 14 years of age, it may weaken and even become extremely nearsighted.