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What is the standard of normal eyesight? Is 1.0 eyesight normal

What is the standard of normal eyesight? Is 1.0 eyesight normal

The eye is an important organ for a person to perceive the world. According to the first global vision report released by the World Health Organization, more than 2.2 billion people in the world are blind or have visual impairment, of which more than 1 billion are caused by failure to prevent or lack of necessary treatment. What does vision mean? What is the standard of normal vision?

What is the standard of normal vision?

Many people think it is normal as long as their eyesight can reach more than 1.0. In fact, 1.0 vision can only show that part of a person's vision is normal.

Strictly speaking, the standard of normal vision also includes the following:

1. Central vision: that is, people usually look at the vision determined by the vision chart, including far vision (look at the vision chart 5 meters away) and near vision (look at the vision chart 30 cm away). The performance of hyperopia patients is that far vision is better than near vision; Myopia is the opposite. Astigmatism patients have poor far vision and near vision. When the near and far visual acuity reaches more than 0.9, it can be said that its central visual acuity is normal.

2. Peripheral vision: when the eyes are looking at a certain target, whether the visible range in the non gaze area is large or small is called peripheral vision, which is often called residual light. Generally speaking, the range of normal people's peripheral vision is quite large, up to 90 degrees on both sides, 60 degrees above and 75 degrees below. Patients with myopia and night blindness have poor peripheral vision, and some fundus diseases can also cause peripheral vision loss.

3. Stereoscopic vision: stereoscopic vision is a kind of the most advanced vision, that is, on the basis of normal vision in the center of the two eyes, through the coordination of the two hemispheres of the brain, we can feel the distance relationship between objects in space. Some people have normal central vision but abnormal stereoscopic vision, which is called stereoblindness in medicine.

Although we usually only check the central vision, in medicine, only when the central vision, peripheral vision and stereoscopic vision meet the physiological requirements can we be regarded as normal vision.