Pupil dilation, also known as pupil dilation, is a common method of ophthalmology to check eye diseases. Depending on the drug used, the pupil recovery time varies, such as tropicamide eye drops, the pupil can usually recover in 4-5 hours after the drug is used; atropine eye drops, the pupil can return to normal in about half a month. Children’s crystalline adjustment ability is strong and the adjustment range is large, so it is difficult to relax the adjustment in a short time during the optometry. In clinical practice, pupil-dilating drugs are used to relax the ciliary muscle, which temporarily reduces the eye’s adjustment power and dilates the pupil for a period of time, making the optometry results more accurate. Dilating medications include fast and slow dilating agents, such as tropicamide, which is a fast dilating agent that can restore the pupil in 4-5 hours after being administered, and atropine sulfate ophthalmic ointment, which is a chronic dilating agent that can last for about 2 weeks. Patients should avoid looking at near places, play more outdoor sports, and avoid direct light on the eyes, and wear sunglasses when going out to avoid direct light into the eyes, which may damage the macular area of the eyes.