If a patient has myopia in the left eye and normal vision in the right eye, it is called refractive error, which is usually caused by congenital developmental abnormalities and may also be related to eye habits. Refractive error means that the refractive error of both eyes is not the same, which may cause the patient to have double vision, dizziness and other uncomfortable symptoms. Refractive error is usually caused by congenital developmental abnormalities, which can be detected through an optometry test. In addition, bad eye habits can also lead to refractive error. If there is a big difference between the refractive errors of both eyes, it is usually not possible to correct it by wearing frames, because the magnification of the lenses of the two eyes is different, which is very easy to cause double vision, and the patient can wear contact lenses or refractive surgery to improve vision. Patients should also pay attention to develop good eye habits to avoid further growth of refractive error. It is recommended that patients with refractive error should consult a doctor in a timely manner to assess their condition and follow the doctor’s instructions for treatment.