Alternate binocular use means that the lens is designed to move in the direction of gaze across the cornea so that the distant and near areas can be almost completely covered by the pupil. The distance or near vision allows alternate selection of vision through different areas of the pupil. Alternating vision occurs in cases where both eyes have good visual acuity and both eyes can focus on the target, so both eyes can be used alternately. The eye may not have any symptoms. The diagnosis of alternate use of both eyes can be made based on the results of binocular optometry. 1. Mild refractive aberration may be asymptomatic. 2, monocular vision Refractive aberration exceeds a certain degree, the monocular function of both eyes is destroyed, in the stage of immature visual development, in order to avoid the interference of blurred objects, will involuntarily take the inhibitory effect, the child is not monocular, but monocular monovision, that is, only use the eye with better vision to see things, the other eye is abandoned, monocular vision without normal depth perception and stereo vision. 3, amblyopia After the formation of monocular vision, the retina of the primary eye is constantly subjected to normal visual stimulation, and through the visual pathway to the visual information to the visual center to form vision, its visual function can be normal development, the blurred image of the disused eye and the information generated by it is inhibited, the visual center does not respond to the visual information of the eye, and the formation of amblyopia, in general, the degree of refractive error of the amblyopic eye is greater than that of the The degree of amblyopia is related to the age at which the refractive error occurs, and the younger the age, the more severe the degree of amblyopia may be. The development of myopic refractive aberrations occurs later, rarely during the sensitive period of visual function development, and even if myopic refractive aberrations cause amblyopia, the degree is often mild. 4, strabismus Amblyopic eyes are not necessarily accompanied by strabismus, but if the eye’s visual function is suppressed for a long time and abandoned, strabismus is likely to appear. 5, alternate vision occurs in cases where both eyes have good vision, both eyes can focus on the target, and both eyes can be used alternately, another situation is that the child has one eye for myopia, the other for orthopia or mild hyperopia, will involuntarily use the near-sighted eye when looking at the near, and use the orthopia or hyperopia when looking at the far, forming a pattern of alternate use of both eyes, although only one eye is used each time, but because the adjustment and collection are not used when looking at the far and near, so There may not be any symptoms.