A mydriasis should be treated as soon as it is detected, and if an abscess forms, the best time to incise and drain it is when the abscess is mature. A mydriasis is an acute purulent inflammation of the sebaceous glands near the lid or eyelash follicles, mainly due to bacterial infection, so patients found with mydriasis should be treated immediately at an ophthalmologist, otherwise the infection may spread and lead to serious complications such as cellulitis and sepsis. Early wheals have not yet formed an abscess and can be treated with antibiotic drops and antibiotic eye ointment under the guidance of an ophthalmologist, or oral antibiotics if symptoms of systemic infection such as fever occur. When the abscess indicates that white pus spots can be seen and there is a fluctuating sensation when touched, it indicates that the abscess is mature, at this time, incision and drainage treatment can be carried out, and the abscess can be cured after about 1 week. Patients with mydriasis should pay attention to rest, keep the eye clean, and apply hot compresses early in the course of the disease to promote recovery.