Since the medication used to dilate the pupil paralyzes the ciliary muscle of the eye, accordingly, the amount of pseudomyopia that occurs due to ciliary muscle spasm can be relieved, and therefore, the amount of myopia after dilation of the pupil of the eye is not the same as that at the beginning. The pre-dilated eye includes both true myopia and pseudomyopia, and tends to be higher, whereas most of the post-dilated eye includes only true myopia, and tends to be lower. This tends to be common in children up to twelve years of age, as the ciliary muscles are prone to spasm and pseudomyopia in this period. In the clinic, dilated eye examinations are necessary to clarify the refractive status of the eyes or to correct vision with spectacles.