Amblyopia, low vision, and blindness are all diseases that seriously impair visual function, and there is a certain relationship between the three. Low vision: refers to the visual dysfunction that cannot be improved by surgery, medication or ordinary glasses, mainly including vision loss and visual field reduction, the best corrected visual acuity in both eyes is lower than 0.3 and equal to or better than 0.05; the best corrected visual acuity in both eyes is lower than 0.05 is called blindness. Amblyopia: no obvious organic lesions in the eye, mainly caused by functional factors, corrected visual acuity is less than 0.9.