Nowadays, there are more and more “small glasses” in kindergartens and campuses, and many parents feel that once their children put on glasses, it is difficult to take them off, so some parents do not want their children to wear glasses too early. If it is myopia, but also to see whether it is true or false, the fundamental way to accurately determine is to go to a regular hospital to implement the “pupil dilatation optometry”. The so-called “pupil dilatation optometry” is the process of determining the nature and degree of refractive error in a child’s eyes due to structural factors (such as the relative size of the eyeball and its related structural components such as the cornea and the light gathering ability of the lens) by using a dilating agent to put the eyes in a completely relaxed state and then, after the pharmacological effects of the dilating agent have worn off, the child’s eyes will be examined. Then, after the pharmacological effects of the diluent have worn off, the nature and degree of refractive error of the eye under normal operation of the eye’s own focusing system will be examined, and finally, the results of the two states will be taken into account to arrive at a prescription suitable for the child’s eye needs. In general, after the above standardized examination, children with myopia of 75~100 degrees or more, farsightedness of 200~300 degrees or more, hyperopia or myopic astigmatism of 50 degrees or more, and certain obstacles in seeing distant targets, should be promptly fitted with glasses, rather than rejecting glasses on the basis of emotion, let alone blindly fitting them. Otherwise, children will habitually squint and tilt their heads because they can’t see clearly, which affects the normal development of the form, and at the same time, because the eyes are under long-term tension and very fatigued, it will make myopia develop faster. What’s more, some children, due to the critical period of functional development (generally considered to be 2~8 years old), can not see clearly for a long time, and the fundus of the eye does not get enough stimulation, and will also develop amblyopia (a common eye disease in children, the basic performance is to wear a mirror best visual acuity is lower than the lower limit of the reference value of the visual acuity of normal children of the same age, it is currently believed that on average about 3 out of every 100 children in China suffer from this disease) in the future, even if wearing a mirror or Surgery will not improve or restore vision, affecting normal learning and employment! Pupil diluents are a class of drugs commonly used in ophthalmology for eye examinations and treatment. The commonly used pupil diluents in China are atropine, postmatropine, and tropine aqueous, of which the duration of action is 3 weeks for atropine, 3-7 days for postmatropine, and 5-10 hours for tropine aqueous. The younger the patient, the stronger the regulation, and to control the regulation, we need to use drugs with a strong “pupil dilation” effect, otherwise the regulation of the eye is not sufficiently controlled, which will directly lead to the inaccuracy of the optometry results. In our daily practice, we often encounter cases in which our farsighted eyes are mistakenly fitted with nearsighted glasses and nearsighted glasses are higher than the actual prescription of the eyes due to the non-use or incorrect use of dilating medication. This can have a negative impact on a child’s eye development. The main pupil dilator currently used in children is 1% atropine ophthalmic ointment (gel), which is applied to both eyes twice a day for three days, with an examination on the third day. The main side effects of this pupil dilator are that during the 2-3 weeks of the drug’s action, especially the first week, it is difficult for children to read and write at close range because the eyes themselves cannot focus; due to the dilated pupils, there is a feeling of photophobia in a strong light environment, and most of the above discomfort begins to decrease after 1 week of medication and basically disappears after 2-3 weeks. In addition, due to their constitution, individual children may experience allergic symptoms such as eye redness, swelling, and itching after using pupil dilators, but most of these symptoms disappear within a short period of time after stopping the medication and do not leave any “after-effects. In some cases, the excess medication may flow through a long, thin channel from the eyes into the nose and throat, where it is absorbed by the mucous membranes, resulting in mild redness of the skin on the face and neck and thirst. Even if the aforementioned phenomenon occurs, it will subside in a relatively short period of time if the child is given more water. In addition, there are very few children who, due to the structure of the eye, may experience elevated intraocular pressure after pupil dilatation, which can manifest as eye swelling and headaches. In such patients, the standardized examination by an eye care professional before dilating the pupil can usually detect and reasonably choose other optometry methods in a timely manner. Once misused, the medication needs to be stopped and treated as an ophthalmic emergency as soon as possible to avoid further damage to the eye. As mentioned above, it is not right for parents to ask for a “quick fix” or refuse to dilate their child’s eyes because they are worried that the dilated pupils will affect their child’s studies, or because they are afraid that the dilated pupils will cause damage to their child’s eyes, or that they will easily perform dilated eye examinations on their child without being examined by a professional ophthalmologist from a regular institution. It is a wise choice to have your child receive regular eye examinations from a regular institution to detect any problems in the development of the child’s visual function and to receive timely and standardized medical care.