Ophthalmologists often propose to dilate the pupil for an optometric examination when measuring myopia, hyperopia or astigmatism in young students, especially children. Some people ask, “Why do I need to dilate my pupils?” This is because when the doctor gives you a dilating eye drop, the muscles that normally regulate the eye become paralyzed and stationary, and the pupil is dilated. At this time, the doctor to your dilated pupil for the examination of the shadow optometry (i.e., a method of checking the degree of glasses), so that the number of glasses found to be accurate, otherwise, due to the muscle movement in the eye caused by the adjustment effect will affect the accuracy of optometry. Some people think, “Will dilated pupils damage my eyes? No, because the effect of this dilating drug is temporary and will disappear after a certain period of time. This is because under normal circumstances, when our eyes are looking far or near, the muscles in the eyeball will play a regulating role to ensure that external objects can be seen clearly both near and far. When the pupil is dilated, the muscles in the eye are paralyzed, so the original regulation to ensure the clarity of external objects disappears, so that when we look at something, especially at close range, it appears more blurred than before, but this is also a temporary phenomenon. When the effect of the dilated pupil disappears, the motor function of the muscles in the eye is restored and the regulation of the intraocular muscles is revived, so that you can see as clearly as before. How long does it take for the dilated pupil to return to its original state? Generally, it takes about a week, but there are differences in the types of medications, such as a rapid pupil dilator in recent years, which can dilate and restore the pupil on the same day, but because this drug is not yet produced in China, it cannot be used universally, and the most commonly used eye drops for children and teenagers are “atropine” eye drops to dilate the pupil, which takes about two weeks to recover. It takes about two weeks to recover. Therefore, when you or your child wants to receive a dilated eye exam, it is important to schedule it so that the blurred vision after the dilated pupil does not interfere with work and school, such as before and after exams, when homework is stressful, this is not a good time for a dilated eye exam to avoid difficulties at work and school.