Difficulty in focusing the eyes is mainly seen in the following cases: 1. In patients with intermittent strabismus, the eyes are strongly adjusted when they are young and the brain can fuse two different objects together. However, as the ciliary muscle adjustment function decreases with age, the eye fusion function also decreases, making focusing difficult. If the symptoms are obvious, strabismus correction surgery is required.2. High astigmatism or myopia and hyperopia that have not been corrected, refractive errors that are not accurately corrected, imaging is not clear, the ciliary muscle needs to be highly regulated, which can easily cause adjustment fatigue, which in turn causes focusing difficulties when switching between near and far, and requires a period of adaptation to see clearly. It is recommended that patients go to the regular ophthalmology, standardized optometry. 3, refractive aberration people, the two eyes imaging size is not the same, when the brain adjustment fatigue, there will be focusing difficulty symptoms, it is recommended to wear contact lenses, reduce the gap between the two eyes.