Whether or not open angle glaucoma is serious depends on the degree of visual impairment and the cause of the disease. If the visual impairment is severe and the cause of the disease cannot be found, the condition will naturally be more serious. Open-angle glaucoma is one of the types of glaucoma. As the disease is relatively insidious, it often develops into a middle to late stage when the patient is diagnosed with the disease, and if not treated in time, it will lead to irreversible visual function damage and ultimately blindness. Open-angle glaucoma can be divided into two different types: primary and secondary. Because primary open-angle glaucoma has an unknown etiology, it is difficult for patients to recover from the disease even if they receive standardized treatment in time if their visual function is severely impaired at the time of diagnosis. The severity of secondary open-angle glaucoma depends on the degree and duration of high intraocular pressure (IOP), as well as the primary disease. If the primary disease itself is more severe, or if the IOP has persisted for a longer period of time, then the individual’s condition will be more severe. In conclusion, individuals need to recognize the seriousness of open-angle glaucoma and seek medical attention when symptoms are suspected, so that the disease can be diagnosed and treated at an early stage, thus preserving their visual function and reducing the risk of the disease.