The traditional definition of amblyopia: According to the diagnostic criteria specified by the National Amblyopia and Strabismus Prevention and Control Group of the Chinese Medical Association in 1996 and adopted at the working meeting of the National Amblyopia and Strabismus Prevention and Control Group of the Chinese Academy of Ophthalmology in April 1996, amblyopia is classified as amblyopia when there is no obvious organic lesion in the eye and the distance visual acuity is ≤0.8 and cannot be corrected due to mainly functional factors. The latest definition of amblyopia: The definition of amblyopia in the 7th edition of Ophthalmology, edited by Zhao Kanxing, is a decrease in best-corrected visual acuity in one or both eyes caused by abnormal visual experiences (monocular strabismus, refractive aberration, high refractive error, and form deprivation) during the period of visual development, with no organic pathology on eye examination.