Sudden blurring and double vision in the eyes, if it is transient, it is considered to be related to visual fatigue and dry eye syndrome. After using eye fatigue, it causes a transient change in refraction, so there are blurred, vague and heavy shadows. Pay attention to eye rest, hot compress, massage or look into the distance, the symptoms can be relieved, usually treated with artificial tears eye drops. If persistent blurring and double vision, you need to visit the ophthalmology clinic. Monocular diplopia is mostly caused by eye diseases and requires routine eye examination to exclude the possibility of fundus, especially macular degeneration. Binocular diplopia may be related to paralysis of one or more extraocular muscles, or may be related to psychiatric factors, and some patients will need further assistance from neurology.