Ankylosing spondylitis causing iritis is more serious. Ankylosing spondylitis can lead to extra-articular lesions, and involvement of the eye can lead to iritis. Iritis is often a condition in which the eye is damaged due to the production of immune complexes, and patients who develop iritis may experience blurred vision or vision loss. Iritis is an inflammation of the iris of the eye, which can also aggravate the condition of ankylosing spondylitis if the inflammation continues to develop. Iritis may precede the onset of the disease, or occur during a quiet period of the disease, and it is prone to recurrence, usually in both eyes at the same time, and in severe cases, it may be associated with cataracts and glaucoma, among other things. Therefore, ankylosing spondylitis caused by iritis is more serious, it is recommended that patients should consult the rheumatology and immunology department in a timely manner, actively cooperate with the doctor, and follow the doctor’s instructions for regular use of medication.