A 5-year-old child whose vision is found to be only 0.5 when checked is relatively somewhat abnormal, as a child around the age of 5 should have a vision range between 0.8 and 1.0. If it is significantly lower than 0.8, it means that there is some problem with the vision. At this point, you should first go to the hospital for an optometry, especially dilated pupils and optometry, to be able to get a relatively accurate refractive error, after which glasses can be fitted according to this refractive error. If the vision can be improved after wearing glasses, it means that it is caused by refractive error, and the glasses may need to be worn for a long time. If you still can’t improve your vision with glasses, you may have amblyopia, and not only should you wear glasses according to your refraction, but you may also need some masking and visual function training to gradually improve your vision.