The human eye is a closed sphere, and the normal eye is under a certain pressure. When the pressure inside the eye exceeds the highest level that the eye can tolerate, it causes damage to the optic nerve and a series of visual impairments such as visual field defects and vision loss are called glaucoma. Glaucoma can be divided into two categories, primary glaucoma and secondary glaucoma, according to its etiology. Patients with primary glaucoma generally have anatomical factors, such as small eye size, short eye axis, hyperopia, shallow anterior chamber, etc. Glaucoma may be triggered if there are triggers such as mood swings, staying in dark places for too long, reading with head down for a long time, etc. Secondary occurrence of glaucoma is mostly due to trauma, inflammation, hemorrhage, tumor, etc., which destroys the structure of the atrial angle and causes the atrial fluid drainage to be obstructed, resulting in an increase in intraocular pressure. In conclusion, glaucoma is caused by the inability of the water generated in the eye to drain properly. Glaucoma is one of the most common blindness-causing eye diseases. Generally speaking, glaucoma cannot be cured, but it can be controlled. Once diagnosed, it should be treated promptly and reviewed regularly at the hospital throughout your life. Because any tissue damage caused by glaucoma to the eye is irreversible, it can lead to permanent blindness if not treated promptly. For early detection of glaucoma, self-testing is required: 1. Iridescence: This is a very specific symptom at the onset of glaucoma, which occurs every night. When looking at lights, especially when looking at round light bulbs, a colorful halo can be seen around the light, like a rainbow after a rain. 2. Foggy vision: There is a momentary blurring of vision, as if looking at the outside world in a fog. If the symptoms are mild and disappear after a good night’s sleep, the symptoms can disappear. 3. Eye swelling and pain: often occurs at the same time as foggy vision, but also separately. When you have the symptoms of eye swelling, please do not forget the possibility of glaucoma. 4.Migraine headache: Some patients with chronic glaucoma often have migraine headache or full headache, so you can see an ophthalmologist to see if you are suffering from glaucoma. 5. People with confirmed glaucoma in one eye may also have glaucoma in the other eye if one of the same symptoms occurs in that eye. According to the above performance, once you predict the possibility of having glaucoma, you should go to the hospital to check and confirm the diagnosis in time.