The patient, Master Wang, is a 50-year-old technical worker, who worked overtime from June to August 2014 due to busy work and was very fatigued, and then developed a strange symptom – double vision, that is, seeing everything with double vision (diplopia), blurred, while the monocular vision is normal, the symptoms are sometimes mild and sometimes heavy, often accompanied by dizziness In severe cases, it became a problem to go down the stairs, so he could not continue working and had to stop working and rest at home. The patient then went to the neurology department of an outside hospital, and after symptomatic treatment, his symptoms were not relieved, and he still had binocular diplopia from time to time. In early September last year, the patient was referred to Long March Ophthalmology, where I performed a detailed eye examination and found that the patient’s upper eyelids were slightly swollen and the right eye was slightly restricted in turning downward. The patient was finally found to have a thickening of the superior and medial rectus muscles in the right eye and a slight thickening of the superior medial rectus muscle in the left eye, and FT3 and FT4 were both significantly higher than normal. 1.What is diplopia? Diplopia is a symptom of ophthalmology, which means that the patient has double vision, one object is seen as two objects (double vision), and the further away the distance the double vision increases, and patients with mild degree will think that the vision is blurred at first. If there is double vision in one eye, it is called monocular diplopia; if there is no double vision in one eye, but double vision in both eyes, it is called binocular diplopia. In the case of binocular diplopia, wearing glasses cannot relieve the problem. Due to the double vision and the difficulty of seeing, patients are often accompanied by dizziness and discomfort, and in severe cases, they cannot even walk normally and are forced to take sunglasses or black cloth to cover one eye to improve their vision, which seriously disturbs their life and work. 2, how to identify whether it is monocular diplopia or binocular diplopia? A simple way to check yourself is to cover one eye and look at something with the other eye. If there is double vision in one eye, it is monocular diplopia. Monocular diplopia is often seen in refractive errors, cataracts and other refractive interstitial clouding, double pupils or oversized iris root incisions, and is generally unrelated to eye muscle movement and paralysis, while binocular diplopia is mainly caused by eye muscle movement imbalance, and eye muscle movement imbalance may be a problem of the eye muscle itself, or it may be a problem with the nerves that innervate the eye muscle, in short, as long as the eye position or movement of both eyes is not coordinated or balanced, diplopia In any case, diplopia occurs when there is an imbalance in the position or movement of the eyes. There are six extraocular muscles in one eye, and a problem with any one of them may cause an imbalance in the eye movements of both eyes and lead to diplopia. Clinically, binocular diplopia is more common than monocular diplopia. 3. What are the common causes of binocular diplopia? As far as the eye muscle is concerned, common causes of eye muscle problems include trauma, surgical injury, thyroid-related eye disease, inflammatory pseudotumor, post-strabismus surgery, post-bulbar parabolic injection, parasites, metastatic cancer, etc.; common causes of nerve problems innervating the eye muscle include trauma, surgical injury (including eye surgery and cranial surgery), diabetes, nasopharyngeal cancer, craniosynostosis, etc. 4.What should I do after diplopia occurs? Do not panic, it is recommended to go to an ophthalmology specialist for examination. The doctor will conduct various eye examinations such as refraction, eye ultrasound and eye movement according to your symptoms to initially clarify the direction of diagnosis, and also to exclude myasthenia gravis, brain lesions and other conditions. An earlier and correct diagnosis can help patients avoid missing the best time to treat their condition. 5.What are the tests to confirm the diagnosis of thyroid-related ophthalmopathy leading to diplopia? Thyroid-related ophthalmopathy is a common cause of diplopia. Your doctor will initially examine your eye appearance and eye movement function in the clinic, and use eye ultrasound and MRI to check whether there is thickening of your eye muscles, and also draw blood to check thyroid serology indicators and thyroid-related antibodies. 6. How to treat diplopia caused by thyroid-related eye disease? If the doctor assesses that you are in the resting phase and your diplopia is stable for more than six months, you can undergo surgery. Surgery to correct diplopia in hyperthyroidism is simpler than orbital decompression surgery. Generally speaking, this surgery can basically reduce double vision in the frontal and downward directions, but some people need two surgeries due to the different degrees of each person’s condition. The patient mentioned in this article, Master Wang, was diagnosed in our ophthalmology department and given 2 courses of standardized impact treatment, and the symptoms were then relieved and stabilized, and had orbital decompression surgery in April this year, and then had bilateral diplopia correction surgery, after which the double vision basically disappeared, and happily went back to work and live normally.