Visual fatigue is a common clinical phenomenon, the formation of the main causes are: 1, caused by strong light stimulation surface, manifested as photophobia, lacrimation. 2, refractive error, strabismus caused by, manifested as the eye, long vision then eye congestion. 3, too long with the eyes, such as reading for too long, long use of video, etc., so that the eye muscle is too tense, manifested as eye distension, long vision is less clear vision, accompanied by dizziness, headache, and even nausea, vomiting, thinking about sleep, etc. 4, external eye disease, such as conjunctivitis, keratitis, blepharitis, etc., easy to cause, manifested as increased eye congestion, increased secretions, foreign body sensation, itching and astringency. 5, wearing glasses inaccurate degree or lenses improperly caused, manifested as visual fatigue began after wearing glasses, with dizziness, eye swelling, nausea, take off the glasses are eliminated. 6, improper illumination of the working environment, or long-sighted target shaking caused by, manifested as leaving the bad gaze environment eye fatigue relief obviously.