There are two types of eye medications commonly used clinically for pupil dilatation, the slow-acting atropine and the fast-acting tropicamide, the fast-acting tropicamide ophthalmic solution, the main components of which are 0.5% tropicamide and 0.5% phenylephrine, which have a parasympathetic inhibition effect and can cause pupil dilation and ciliary muscle paralysis after dispensing. Atropine is a long-acting pupil dilator with similar main effects to tropicamide, and it takes 3 days after application of atropine drug to achieve drug effect and maintain it for 3-4 weeks, which can affect children’s daily life and learning during the drug administration. Compared to the two types of pupil dilators, rapid dilators do not paralyze the ciliary muscle as much as long-acting dilators, which means that the results of optometry are more accurate after dilating with long-acting dilators than with rapid dilators. Children under 12 years of age are in a critical period of visual development, and the accuracy of refractive testing is very important at this time. The first choice is atropine for children under 12 years of age, and tropicamide for adolescents over 12. There are two types of eye drops for pupil dilatation: Atropine, a long-acting dilatant, is recommended for children under 12 years of age for more accurate prescriptions, while tropicamide is recommended for adolescents over 12 years of age, without affecting their lives and studies. In addition, there is a medium-rate pupil dilatation drug, postmastropin, which has a longer duration of action than atropine, about 2-3 days longer than compound tropicamide, and is suitable for patients aged 12-15, but is currently mostly off sale in China.