Congenital cataract is the main cause of blindness in children. With the rapid development of microscopic technology, continuous innovation in surgical procedures, and improvement in the accuracy of IOL prescription calculation, more and more children are gaining the hope of reconstructing their visual function. Since babies under 3 years old cannot recognize the visual acuity chart, it is difficult to objectively evaluate the effect of postoperative amblyopia training and cannot predict the recovery of visual function after surgery. The visual evoked potential (VEP) is an electrical signal from the cerebral cortex in response to a visual stimulus, which originates mainly from the cone cells within 20° of the retinal center and reflects the neural pathway from the retinal ganglion cells to the visual cortex. This method of recording helps the physician to evaluate the degree of visual function of the child, is suitable for infants and children who do not cooperate with the examination, and is an important scientific tool to evaluate visual function in the long-term follow-up of children with congenital cataracts.