What is the standard of normal vision and what is the standard chart of eye vision

1. Central vision: that is, the visual acuity determined by people usually looking at the eye chart, including distance vision and near vision. Patients with hyperopia present with better distance vision than near vision; The opposite is true for patients with myopia.

People with astigmatism have poor distance and near vision. When the near and distance visual acuity is above or above, the central visual acuity is normal.

2. Peripheral vision: When the eyes are fixed on a certain target, the range that can be seen in the non-fixation area is large or small, which is called peripheral vision, which is often referred to as "residual vision". The range of peripheral vision in a normal person 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. Stereopsis: Stereopsis is a kind of superlative vision, that is, on the basis of normal vision in the center of the two eyes, through the harmony of the two hemispheres of the brain, you can feel the distance relationship between objects in space. Some people have normal central vision but abnormal stereopsis, which is medically called stereopopia.

The visual criterion is that the logarithmic eye chart is that the visual acuity should be checked below to determine whether there is a refractive error. The visual criterion is, for a logarithmic eye chart, that is. Normal vision is generally above, for abnormal vision can be, just like our exams, passing 80 points, such as 70 points, 80 points, 90 points, or even higher.

And in the above, for example, the eyesight, that is extraordinary vision, just a little better than normal vision. Therefore, when we perform a physical examination, as long as the vision is achieved, we consider it normal. When vision is low, we usually do some tests to determine if we have eye disease, whether we have myopia, farsightedness or astigmatism.

Many people think that as long as the vision can reach 1 0 or more, it is considered normal. In fact, a visual acuity of 1 0 can only indicate that a person's partial vision is normal. Criteria for normal vision also include:

1. Central vision.

That is, people usually look at the visual acuity chart to determine the visual acuity, including distance vision (looking at the eye chart from 5 meters away) and near vision (looking at the eye chart at 30 centimeters). Patients with hyperopia present with better distance vision than near vision; The opposite is true for patients with myopia. Patients with astigmatism have poor distance and near vision, and when the distance and near vision reaches 0 9 or above, it means that their central vision is normal.

2. Peripheral vision.

When you gaze at a target, the range that can be seen from the non-fixation area is large or small, which is called peripheral vision, which is often referred to as "residual vision". Generally speaking, the range of peripheral vision of normal people 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.

Stereopsis is a kind of highest-level vision, that is, on the basis of the normal center of the two eyes, through the harmony of the two hemispheres of the silver and the brain, the front calls to feel the distance relationship between objects in space Some people have normal central vision, but stereoscopic vision is abnormal, which is called stereoscopic blindness in medicine.

In medicine, normal vision can only be counted if the central vision, peripheral vision, and stereophesis all meet physiological requirements.