Nine-year-old child bare eye vision 4.5 degrees and 4.9 degrees, 4.5 vision is poor, but not particularly serious, need to be determined by optometry. Normal bare eye visual acuity degree is 5.0 degrees, below 5.0 degrees belongs to vision loss, and the current vision of 4.5 degrees in one eye and 4.9 degrees in the other eye belongs to moderate poor vision, but is not particularly serious, through timely correction, the vision can be made to improve. If the naked eye visual acuity is 4.5 degrees or 4.9 degrees, we should also consider mild astigmatism, nearsightedness or mild farsightedness, which may lead to vision loss, and the visual acuity will not reach 5.0 degrees. However, vision loss is not particularly serious at this time, and most children do not experience symptoms such as blurred vision or difficulty seeing. If vision loss is detected, it should be dealt with in a timely manner so that it does not continue to affect normal vision. Nine-year-old children with naked eye vision of 4.5 degrees, 4.9 degrees, it is recommended that as soon as possible optometry, or refractive testing, to understand the causes of low vision, and then early treatment, if necessary, should be laser surgery.