Diplopia refers to double vision with double images, and some patients may also suffer from dizziness, headache and other uncomfortable symptoms. Diplopia occurs when the visual center of the brain fails to fuse the same object at a non-corresponding point on the retina, which is often called double vision. Patients with diplopia may see one object as two. Some patients may experience dizziness and other discomforts due to double vision, while diplopia caused by diseases such as posterior scleritis is often accompanied by headache, eyelid edema, congestion and other discomforts, and diplopia caused by thyroid-related eye diseases is often accompanied by protruding eyeballs. Patients with diplopia caused by thyroid-related eye diseases are often accompanied by protruding eyeballs. It is recommended that patients with diplopia should consult a doctor in time to assess their condition and follow the doctor’s instructions.