Under-concentrated intermittent exotropia sometimes occurs after encephalitis, diphtheria with streptococcal infection, macromonocytosis and car accidents. Some patients have a gradual onset over many years with slowly worsening symptoms. Hypoconcentration with hyporegulation sometimes occurs after encephalitis, streptococcal diphtheria, macromonocytosis and car accidents. Some patients have a gradual onset over many years with a slow worsening of symptoms. There are no specific findings in the medical history. Some have a history of high fever in childhood, so some authors suggest that subclinical encephalitis may be the cause of the disease. These patients have more severe symptoms and, unlike the functional abnormality category, do not respond to orthostatic visual training and rarely resolve. The patient has a distant or even inability to focus the near point of assembly; the near point of accommodation is significantly distant. the AC/A is extremely low9 or even 0. Stimulation of the accommodation mechanism with a negative spherical lens does not induce an assembly response. The treatment method mostly uses positive spherical lenses and bottom-inward trigeminal lenses to help reading. The principle of giving prescriptions is to give as few degrees of trigeminal and positive spherical lenses as possible, as long as comfortable reading vision can be obtained. In order to maintain good correction, it is important to review the glasses regularly and adjust the prescription at any time. Therefore, applying compression to the ortho-phthalmoscope with a tricorder is a convenient treatment method. Pupil constrictors can increase the degree of exotropia when looking at the near and make the patient’s symptoms worse. Therefore, these drugs are not used clinically. Surgical treatment with bifocals is also a treatment method, and surgery is mostly used to shorten the internal rectus muscle of both eyes.