Children with vision loss first need to undergo a dilated pupil optometry, in addition to a strabismus examination, slit lamp microscopy, and, if necessary, fundus photography and other ancillary tests. In general, for children aged 12 years and below, dilated optometry can be considered one of the most important examination programs. Because of this age children’s lens regulation function is too strong through atropine, tropicamide and other drugs dilated pupil to lift the regulation of the impact of optometry, accurately on myopia, hyperopia, etc. to make a judgment, to determine whether the children’s vision loss is related to refractive error. In addition to pupil dilation, children’s vision loss may also be due to strabismus, trauma and tumors, etc. Therefore, it is necessary to improve the masking method, slit-lamp microscopy and fundus photography and other auxiliary examinations to clarify the cause of vision loss. It is recommended that children with vision loss consult a doctor promptly to evaluate their condition and follow the doctor’s instructions for treatment.