The monocular masking aversion test is a test for amblyopia in children in which the child’s eyes are covered alternately with a mask to see if their behavioral responses are consistent so that they can be compared for differences in vision between the two eyes. If the monocular masking aversion test is positive, it is necessary to complete the examination and follow the doctor’s instructions. 1. Amblyopia is mostly seen in one eye, usually children will refuse to cover the better eye, which will be manifested as crying, face twisting and other refusal reactions. Children with symmetrical vision in both eyes will have the same reaction when covering both eyes; if one eye is obviously resistant to covering while the other is not, it suggests that the difference between the two eyes’ vision is large. 2. A positive monocular masking aversion test suggests that amblyopia may exist and requires high attention. As long as timely intervention is made during the critical period of the child’s visual development, amblyopia treatment can generally achieve better results. It should be noted that the diagnosis of amblyopia cannot rely on a single test indicator, but should be based on the child’s medical history, symptoms, physical examination, and other auxiliary tests for comprehensive judgment. After a clear diagnosis, standardized treatment under the guidance of the doctor, do not blindly self-judgment, so as not to delay the condition.