How long it takes to recover from a dilated pupil cannot be generalized, but is mostly related to the way the pupil is dilated and the medication used. There are two main methods of pupil dilatation that are commonly used in clinical practice, one is rapid pupil dilatation, which is mainly used for adults, and generally the pupil can be dilated in a few minutes with external medication, and the recovery time is faster, about 3-4 hours; the other is slow pupil dilatation, which is mainly used for children under 13 years of age, and most of them choose atropine to dilate their pupils before optometry, and the number of pupils dilated is higher and the time is longer, 3-5 days. It takes about 20 days to restore the normal pupil size. Therefore, the time to restore normal pupils after dilatation is variable, generally faster for adults and slower for children. If any eye discomfort occurs during this process, prompt medical attention is recommended. In addition, patients should develop good eye habits and avoid staying up late.