There are two methods of eye examinations, one is through computerized optometry and the other is through retinoscopy, which gives the approximate refractive power of the eyes, and the means of detection are different for different age groups. For example, for adults, there is no need to dilate the pupil, and computerized optometry or photometry is sufficient. For adolescents or children, a visual function test is required to determine whether dilated or undilated optometry is needed. If dilated pupils are needed, we can also distinguish between fast dilated pupils, small and medium dilated pupils, and slow dilated pupils. After the pupil is dilated, the refractive power is then determined through a photometry or computerized optometry.