The liquid crystal vision chart is a commonly used vision test instrument, mainly used in eye examination, eyeglasses and vision correction. It tests the patient's vision level and condition by displaying letters, numbers, graphics, etc., of different sizes and brightness. The LCD visual acuity chart can be used to measure patients' far vision, near vision, astigmatism, diopter and binocular vision quickly and accurately, and the test results can be saved for analysis and comparison. The LCD visual acuity chart has the advantages of clear display, simple operation, small size, etc., which is suitable for hospitals, optical shops, schools and families.