Optometry is best chosen in the morning, because the eyes after a full night’s rest, can be completely relaxed, when the optometry results are more accurate. If you choose to get glasses when your eyes are tired, the results may be high. This is because when the eyes look at different objects in the distance and near, they mainly rely on the contraction and diastole of the ciliary muscle, which pulls the lens thickness to adjust the focal distance. If you use your eyes for a long time, the ciliary muscle is in a state of fatigue, and the result is not accurate. If you wear such glasses, you may not feel any discomfort at that time, but after some time, you may experience dizziness and dry eyes. In addition, computerized optometry is a commonly used method of optometry, which uses optical focusing to measure the specific degree. However, the mechanical reading of the data, and does not take into account the subjective feelings of the human eye, so computerized optometry with glasses must be tried on for a period of time, such as feeling uncomfortable to re-optometry. Also, the experience of the optometrist is important, experienced optometrist will consider the customer’s eye condition and give a reasonable prescription. In addition, the fundus examination before prescription is often overlooked. On the one hand, fundus examination is to rule out poor vision correction caused by fundus diseases, which should be treated in an eye hospital; on the other hand, it can also screen out people who are not suitable for dilated optometry. For people who have been wearing contact lenses, they should stop wearing contact lenses for 1 to 2 days before going for optometry.