Depending on the type of glaucoma, the symptoms vary. Patients with closed-angle glaucoma often have more obvious symptoms, mostly due to the sudden and complete closure of the atrial angle, which causes a rapid and significant increase in intraocular pressure. Patients may experience typical eye distention, redness, blurred vision, iridopsia (the patient can see a rainbow-like halo outside the light), and sometimes headache, nausea and vomiting. In some patients, the symptoms are not obvious because the atrial angle is partially closed and progresses slowly, or there is mild eye distention and headache that improves with rest, and iridescence at night. Patients with open-angle glaucoma have a slow and gradual development of elevated intraocular pressure, a slight discomfort of headache and eye swelling and eye pain during the early reading time, a rapid increase in myopia for unknown reasons (more than 200 degrees per year), or a gradual decrease in visual acuity, and the phenomenon that optometry and prescription cannot improve visual acuity. A significant number of patients have no symptoms in the early stages, but their visual field is continuously being damaged, so most of these patients do not know they have glaucoma until the visual field damage has progressed to a very serious level or is detected during an occasional eye examination. This makes it even more dangerous. In children, glaucoma is caused by poor eye development. In the initial stage, the eye is enlarged, like a balloon, and the internal pressure is high enough to hold it up, which relieves the pressure, but generally the eye does not have this compensatory function beyond the age of three. Before the age of three the eye will continue to expand, expand to a certain extent the cornea of the eye will be hairy paste off, this time the child will have symptoms. Although children at this age cannot express themselves well, they have some specific actions, such as rubbing their eyes, fear of lights, and watery eyes. Parents should observe their children for such behaviors and bring them to the hospital as soon as possible once they are detected. Secondary glaucoma can be caused by systemic diseases such as diabetes, hypertension, or ocular trauma, or inappropriate use of certain drugs (mostly glucocorticoids, such as dexamethasone), and can appear on the basis of the corresponding medical history, such as eye redness, eye swelling and tearing, etc. A doctor should be asked to conduct slit lamp examination, fundus examination and timely detection of intraocular pressure to clarify.