Human's understanding of binocular vision has a history of more than 100 years. In the process of binocular vision understanding, some new binocular visual function examination tools, some diagnostic concepts of binocular vision abnormalities, and some visual rehabilitation training of binocular vision abnormalities are being applied and developed.

In the 1990s, the French doctor Javal created the orthostatic training method to improve strabismus and binocular abnormalities. In the early 20th century, the British doctor worth invented worth's four lights and synoptophore, and first put forward the concept of three-level visual function in 1921; At the same time, Maddox, another British doctor, invented a Mahalanobis rod lens for detecting esotropia and an improved solid lens for training.

In the 1920s, British physiologist sheard designed 19 step visual examination method and binocular case analysis method, and put forward the concept of binocular single vision clear area in visual optics.

In the 1940s, Swiss doctor Brock designed many training instruments and technologies to work in an open environment to improve the regulation and dispersion functions, such as Brock line.

In 1962, American scientist bjulesz discovered that binocular parallax is the basis of stereopsis and invented random point stereogram.

Binocular vision function is not a simple mathematical calculation of one eye plus one eye, but can produce many functions that cannot be provided by monocular vision. The visual information of the same fixation target received by both eyes is integrated into a complete single target image by the visual center, which is called binocular fusion image, also known as binocular monocision. Binocular fusion image is divided into motor fusion image and sensory fusion image.

Motion fusion image refers to the image formed by the same object point can be focused on the binocular retina and on the corresponding point of the binocular retina through the functions of binocular adjustment, convergence and dispersion, eye functional movement and so on. For example, the abnormal retinal correspondence of binocular image points caused by recessive strabismus when looking at the near target can meet the image fusion needs of both eyes through an appropriate amount of collection or dispersion function, which can be said to simulate the image fusion function of the actual space.

Sensory fusion is the integration of retinal images obtained by both eyes into a unified perception through visual physiological and visual psychological mechanisms. The corresponding binocular retinal images are formed through the motion fusion image. If there is a little difference, it can be "assimilated" through the sensory fusion image. If the similarity of the corresponding binocular retinal images is poor, the sensory fusion image selectively inhibits one of the images, resulting in monocular inhibition. Sensory fusion is the fusion function of constructing visual space.