Hyperthyroidism, which causes eyes to be large and small, can usually be significantly improved or even recovered with treatment. Thyroid-related eye disease is an autoimmune disorder. The lesions involve the orbital rhabdomyosin, smooth muscle, adipose tissue, lacrimal gland and connective tissue. Symptoms of eye discomfort such as dry, watery eyes, congestion, protruding eyeballs, and eye movement disorders can occur. Characteristic eyelid recession and upper eyelid hysteresis can occur due to lesion involvement of the levator muscle. Hyperthyroidism protruding eyes can be improved or even recovered with the help of endocrinologist and ophthalmologist by controlling hyperthyroidism, glucocorticoid shock therapy, surgical treatments (e.g. orbital decompression surgery, eyelid recession correction surgery). In normal life, pay attention to low iodine diet, healthy eye use (such as watching less cell phone and TV, avoiding sunlight stimulation), and so on. In conclusion, hyperthyroidism leads to a large and small eye, it is recommended to consult endocrinologists and ophthalmologists as soon as possible.