The main purpose of having a dilated eye exam is actually twofold: 1) to make the results of the refraction more accurate; and 2) to be able to observe the state of the fundus more clearly, especially the state of the peripheral fundus. After the pupil is dilated, if the refraction is performed, the refraction will be relatively accurate. If the eye is examined in a non-dilated state, it is likely that the prescription will be myopic, which is very common among young people or children who use their eyes at close range for long periods of time, and these two groups of people mainly need dilated eye examinations. In addition, dilated pupils can dilate the pupil, which is very beneficial for fundus observation, especially if there are diseases that require peripheral fundus observation, such as retinal degeneration or retinal fissures, which mostly occur in the periphery and require dilated pupils followed by peripheral fundus examination.