Whether or not a child’s naked eye visual acuity of 4.9 is normal is related to age, if the child is less than 6 years old, the naked eye visual acuity of 4.9 is normal, if the child is already more than 6 years old, the visual acuity of 4.9 is lower than normal. Children’s eyesight develops gradually after birth, usually at the age of about 3 years can already do a vision check, at this time the naked eye vision should be able to reach more than 4.6 at the age of 4 to reach more than 4.8 at the age of 4, at the age of 5 to reach more than 4.9 at the age of 6 years should be able to reach the same as a normal adult of 5.0. It is normal for a child under 6 years of age to have a vision test of 4.9. It is only necessary to closely observe the development of the child’s vision. If the child has already reached the age of 6, and the current visual acuity of 4.9 is lower than normal, the child should go to the ophthalmology department of the hospital in time for examination to see if there are any myopia, hyperopia, astigmatism, amblyopia and other diseases. It is recommended that patients with abnormal vision seek prompt medical attention to evaluate their condition and follow medical advice.