After monocular optometry, achieving the same best corrected visual acuity in both eyes can only indicate that the visual acuity of the two eyes is balanced, but it is the ultimate goal of binocular balance to ensure that the visual balance is achieved on the basis of balanced binocular adjustment. Because if the accommodative power of the two eyes is not balanced, it is easy to cause visual fatigue, and it is also easy to cause the patient's single eye refractive error to increase faster, so it is necessary to perform a binocular balance test after the end of the monocular optometry.

There are three main methods of binocular balance: alternate cover balancing method, prism separation balancing method and polarization separation balancing method. The former method is suitable for insert optometry, and the latter two methods are suitable for comprehensive optometry.