1. central vision: ① hyperopia detection method: At present, there are international standard visual acuity charts and 5-point logarithmic visual acuity charts designed by Professor Miao according to the commonly used mathematical principles in China. It is generally considered that hyperopia (5m) ≥ 1.0 is normal; ② Myopia examination method: The international standard myopia visual acuity chart is divided into 12 lines, and each line uses decimal notation and the standard distance for normal eye examination. General myopia (30cm) ≥ 1.0 is regarded as normal.
2. Peripheral vision: When the eyes look at the object, they can not only see the object clearly, but also see a certain range of objects around the gaze point. The spatial range that can be seen when the eyes are fixed is called the field of vision. The size of the normal visual field can be different due to the size, color, inspection distance, light intensity and background of the target.
In addition, such as the size of eyelid droop, the height of the bridge of the nose and the degree of eyelid droop will affect the visual range. Generally speaking, the normal monocular visual field is more than 55, less than 75, nasal side 60, temporal side 100, and the white visual field is the largest; The range of binocular vision is larger than that of monocular vision.
If there is a decline in vision, you should go to a professional eye institution for examination to determine whether it is caused by ametropia. After wearing glasses, if the vision can reach normal above 0.8, it also means that there is not much problem with the eyes; If you can't reach it, you may have eye diseases or amblyopia. It is best to do a comprehensive eye examination carefully.