Dilated pupils, also known as “ciliary muscle paralysis”, are an important tool for determining the refractive status of adolescents and can be divided into “slow-acting dilated pupils”, “medium-acting dilated pupils” and “fast dilated pupils” depending on the choice of medication used. Depending on the choice of medication used, it can be divided into “slow dilatation”, “medium dilatation”, and “fast dilatation”. The 2018 Myopia Prevention Guidelines state that ciliary muscle paralysis optometry is the internationally recognized gold standard for diagnosing myopia, and recommend that children under the age of 12, especially those undergoing their first optometry, or those with hyperopia, amblyopia, and large astigmatism, must undergo ciliary muscle paralysis optometry, and that children diagnosed with myopia who need glasses need to have their optometry reviewed regularly. The choice of dilating medication is based on the patient’s refraction, the presence of strabismus, the presence of amblyopia, as well as the patient’s age and iris color. “Slow-acting dilatation” is a method of dilating the pupil using 1% atropine, which is usually ordered three times a day for three days, with a follow-up exam on the fourth day. The duration of the medication is about 21 days. The medication of choice for “medium-acting pupil dilatation” is 1% cyclopentone eye drops, which work quickly and can be used 4-5 times within an hour to dilate the pupil and perform a refractive eye examination. “Fast pupil dilatation” is most often performed with compound tropicamide drops, which have the most rapid onset of action and can be done 3-4 times within an hour. Overall, dilated eye examinations are a very effective means of accurately detecting refractive error.