A vision of 0.3 corresponds to a vision of 4.5. 0.3 vision is a decimal record expression, from 0.1 to 2.0. 4.5 vision is a five-point vision expression, these two expressions are different, but the corresponding situation is the same, 0.3 corresponds to 4.5. 0.3 vision needs to be investigated for the cause of vision loss, whether it is due to refractive error, etc., or The vision of 0.3 needs to be investigated whether it is caused by refractive error or other diseases of the eye, such as cataract or fundus disease, and requires prompt medical attention. Under normal circumstances, 1.0 is considered normal vision, but of course, different children have different lower limits of vision values for their age.