A retinal examination is primarily a fundus examination. The precautions for fundus examination are that if the fundus is not visible under a small pupil, it is recommended to dilate the pupil, but before doing so, it is advisable to check the intraocular pressure. If the intraocular pressure is relatively high, do not blindly dilate the pupil, as dilation may trigger a glaucoma attack. If the intraocular pressure is not high, the fundus can be seen more clearly by dilating the pupil. When the fundus is examined at the same time, make sure the patient can see clearly because when the fundus lens hits the macula, the patient will not be able to see clearly for a while, but it will disappear immediately. Patients should pay attention in their daily life, looking at fewer electronic products and consuming less greasy food. Patients should be examined under the guidance of professional doctors, and if any adverse reaction occurs, go to the hospital in time for consultation, and actively cooperate with the doctor’s treatment.