The standard of vision is the opening angle of the smallest character that human eyes can recognize. The visual acuity of normal eyes is above 1.0. Usually, vision refers to the minimum separable vision of the eye, not the minimum visible vision. Therefore, the eye chart reflects the minimum visual angle separated by the two points of the subject's gaze at the target, that is, the minimum separable vision, or 1' visual angle vision, which can represent the subject's best visual function.
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How to protect eyesight
Protect your eyes from the sun. Wear sunglasses that block ultraviolet radiation.
Prevent eye injuries. Wear protective glasses when doing certain things, such as exercising, mowing, smearing or using other toxic gas products.
Eat healthy food. Try to eat more green leafy vegetables, other vegetables and fruits. Studies have shown that if the diet contains high levels of omega-3 fatty acids, such as tuna and salmon, patients' eyes will also benefit.
Do not smoke. Just as smoking is harmful to other parts of the body, smoking can also have an adverse effect on eye health.
Use correct corrective lenses. Appropriate lenses can optimize the patient's field of vision. Regular inspection will ensure that the patient's prescription is correct. There is evidence that wearing too weak prescriptions (insufficient correction) will increase the development of myopia.
Use good lighting. Turn on or increase the light to get better vision. Reduce eye fatigue. Work away from the computer or close to the task, including reading once every 20 minutes for 20 seconds, with a distance of 20 cm.
People's Network-How to protect your eyesight?