The so-called “horn” is the “corner of the room”. The eye is like a water tank, with an inlet pipe and a drainage pipe. The “atrial horn” is the “entrance” to the drain. It is located at the intersection of the cornea and the peripheral iris, almost where the “black eye” meets the “white eye”. “Closed angle” means that the angle of the atrium is closed, which means that the cornea and peripheral iris are adhered to each other, which is equivalent to the blockage of the entrance to the waterway, and closed angle glaucoma occurs. “Open angle” means that the atrial angle is open, which is equivalent to a blockage in the waterway network, and open angle glaucoma occurs. What are the signs of acute closed-angle glaucoma? Acute angle-closure glaucoma has recurrent symptoms. Most attacks occur at night. It often occurs after exertion, anxiety, or fire, with eye swelling, ipsilateral headache, blurred vision, and red and green circles around the light. If the symptoms are mild, they may be relieved within a few seconds to a few minutes, or within a few hours, or after sleep. In severe attacks, the symptoms are severe, with painful eye swelling, blurred vision, severe headache, nausea and vomiting, and delayed ophthalmologic treatment. This is a major attack, which can cause serious damage to vision, or even complete blindness!!! Why should I get laser for closed-angle glaucoma? Patients with closed-angle glaucoma have congenitally small eyes with smaller than normal anterior and posterior diameters, shallow anterior chamber and narrow atrial angle. Without early intervention, the atrial angle can easily close gradually and glaucoma can occur. Laser peripheral iridotomy can improve the narrow atrial angle appropriately, allowing most patients with closed-angle glaucoma to stop developing. As we can see in the figure, the atrial angle is wide and does not close in adhesions in normal people. In the case of closed-angle glaucoma, the angle is very narrow and the iris is bulging. After laser perforation of the iris, the iris can be flattened and the angle can be widened. What should I know about medication? ①Follow your doctor’s instructions and take your medication regularly, don’t stop taking it without permission. ②Wash your hands before you take the medication and press the inner corner of your eye afterwards to improve the utilization of the medication and reduce the side effects caused by the absorption of the medication through the tear sac. ③The most appropriate dosage is one drop per eye, the interval between the use of two kinds of eye medications should be about 5 minutes, do not blink after the eye drops, and do not use them at night during sleep ④Some anti-glaucoma drugs have side effects, you should explain to your doctor before using the medication about your systemic disease and drug allergy history so that your doctor can choose the medication.