Niu Niu, 5 years old this year, is a native of Kaifeng, Henan Province. Niu Niu has a pair of bright black eyes, lively and cute, since childhood, people love. I don’t know when it started last year, Niu Niu like to squint at people. The neighbors joked, “Niu Niu has grown a temper and has a personality.” Mom and dad forced Niu Niu to correct himself, but Niu Niu was still like that, always squinting his eyes to look at things. Someone reminded them that the child might be suffering from strabismus and should go to the hospital for a checkup. They went to the ophthalmology department of a local hospital to see the doctor. Sure enough, the doctor said it was strabismus and recommended surgery to correct it. After Niu had the surgical correction treatment, he recovered for a while. Not long after, Niu Niu started to look at people with squinted eyes again. Mom and dad were anxious and sighed, it was impossible to correct surgically all the time. Slowly, Niu Niu began to walk a little unsteadily, they thought it was because of Niu Niu’s strabismus, and didn’t pay much attention to it. The danger was just creeping up on them. One day, when Niu Niu was playing on the slide in kindergarten, he stumbled and fell down the slide. Fortunately, the kindergarten teacher was by the ladder and helped him in time, otherwise the consequences would have been unthinkable. When his father came to pick him up from kindergarten, the teacher told him that Niu Niu had been very abnormal lately, falling often and always crying, saying that he couldn’t see the blackboard and his head hurt. Realizing the seriousness of the problem, they once again took Niu Niu to the hospital for a checkup. Niu Niu’s vision was severely reduced, and an MRI of his head showed a huge tumor in his brain. The doctor advised them to have surgery. After a friend introduced them to Beijing, the diagnosis was craniopharyngioma. After the surgery to remove it, NiuNiu’s headache has improved significantly and he no longer walks unsteadily or looks at people with squinted eyes, only that his vision is still in the process of gradually recovering. According to the professor of neurosurgery of Sanbo Brain Hospital of Capital Medical University, a considerable number of children with brain tumors are discovered when they come to the hospital for examination because of vision problems. Tumors in the brain, cerebellum and ventricles can invade the optic nerve and cause various vision problems. The craniopharyngioma in the above case is a benign congenital tumor, and visual impairment is one of its common first symptoms. Its growth often involves important structures of the hypothalamus and needs to be completely removed to avoid affecting the growth and development of the child. Unfortunately, due to the lack of knowledge of parents or some non-specialist medical personnel, it often happens that children are misdiagnosed, diagnosed too late or cannot receive effective treatment. If the child’s vision is severely damaged, even if craniotomy is performed to remove the tumor, the damage of vision cannot be fully recovered or even blind. Thus, early detection and treatment of brain tumor is important for the prognosis of treatment. A lot of clinical experience shows that vision problems related to brain tumor have the following characteristics: 1. There is no abnormality in eye appearance, but vision is significantly reduced, accompanied by dizziness and headache. It is easy to be misdiagnosed as eyestrain and myopia. 2. It is often accompanied by visual field defects, i.e., a reduction in the range of what the eye can see, along with a decrease in visual acuity. For example, the strabismus in the above case was caused by visual field defect. Third, it is possible to find optic nerve edema or atrophy during fundus examination. Therefore, the above mentioned alarming vision problems should be considered as alarm signals and parents should bring their children to the hospital for examination as soon as possible to find out the real culprit hiding behind the vision problems.