Children’s eyes are very highly adjustable, and if their adjustment is not controlled, the results of optometry often lead to erroneous conclusions, even treating hyperopia as myopia. The treatment of strabismus and refractive error requires accurate optometry results, so children should be ciliary muscle paralysis, due to the phenomenon of pupil dilation, commonly known as “dilated” optometry. According to the need, often divided into the following two types of optometry: First, slow dilated optometry is often used for refractive examination of children less than 9 years of age. 9-12 years of age children are known to have hyperopia, astigmatism, or severe spasticity of regulation, it is also best to dilate the pupils of optometry in a slow. Children should be treated with 1% atropine eye ointment, applied to both eyes twice a day, often for 3-5 days, as directed by a physician. Do not apply to the mouth and nose. After applying the ointment, apply pressure to the tear duct area bilaterally for 5-10 minutes to prevent the partially liquefied ointment from being rapidly absorbed into the nasal cavity and causing side effects. Do not apply eye ointment on the day of optometry, so as not to affect the observation of the pupil area light and shadow. After the optometry is completed, the child is usually retested after three weeks. The purpose is to compare the static and dynamic refractions before and after the two times, and to choose a suitable refractive error for treatment or correction for the child. Generally the effect of atropine disappears in about three weeks, during this period, the child has symptoms such as shyness vision, dry mouth, unclear near objects, etc. Outdoor sunglasses can be worn and appropriate water. Mistakenly applied to the mucous membrane of the mouth and nose, there will be red face, rapid heartbeat, etc., usually will be relieved by themselves, and in serious cases, sent to the hospital for treatment. A small number of children are allergic to atropine, which often manifests local symptoms far more than systemic symptoms, such as eyelid redness, swelling, conjunctival congestion, at this time, we need to stop using the drug, go to the hospital to consult the doctor. Rapid dilated optometry is often used for refractive examination of adolescents over 12 years old. It can also be used for myopic reexaminers aged 9-12 years old. Some suspected myopic patients aged 7-9 years old who are eager to be examined can use it temporarily during the school year in order not to affect the classes, but they must be rechecked during the vacation to confirm the diagnosis using slow dilated pupil. Contact with the physician or optometrist before the examination, point 0.5% tropicamide ophthalmic solution, every 5 minutes, a total of about 6 times (according to the condition of adjustability and medical advice, there are 4 or 8 times), the last point, but also to close the eyes to rest for more than 30 minutes (some patients have to rest for more than 1 hour), and then you can examine the light. The medication works for about 8 hours and usually does not affect the following day’s classes or daily activities. On medical advice, a retest and prescription can be given after 24 hours.