There are many ways to classify amblyopia, and depending on the cause, amblyopia can be divided into: 1. strabismus: strabismus is one of the most common causes of amblyopia, often monocular amblyopia, where there is a constant, non-alternating strabismus (the most common is internal strabismus), which leads to competitive suppression of visual information and amblyopia in the strabismic eye. 2. refractive error: often binocular amblyopia, infancy, uncorrected refractive error, which can cause amblyopia after it reaches a certain level. After its degree reaches a certain level, it can cause amblyopia. Refractive aberrations: Refractive aberrations between the two eyes (ortho-spherical difference greater than or equal to 1.50D, columnar difference greater than or equal to 1D) are likely to form amblyopia in eyes with high refractive error. Low to moderate myopic refractive error is generally not easy to form amblyopia.4. Formal deprivation: In infancy, congenital or early onset of refractive interstitial clouding or pupil blockage, causing abnormal visual development to form deprivation amblyopia. For example, congenital high-density cataracts, corneal opacities, congenital ptosis, and uncorrected aphakic eyes are all causes of amblyopia.