Dispersal - Kaisan

Japanese: 開散 - かいさん

…In contrast, the muscles that act in the opposite direction to the movement (in the above case, the medial rectus muscle of the right eye and the lateral rectus muscle of the left eye) are called antagonistic muscles. There are two types of incoherent eye movements: convergence (also called convergence) and divergence (also called divergence). Convergence is the function of focusing the gaze on a single point in front of the eyes, and is usually achieved by contraction of the medial rectus muscles of both eyes. …

From "eye"

…When looking at something close, accommodation occurs along with convergence. In contrast, opening the convergent gaze of both eyes is called divergence. The extraocular muscles are innervated by the oculomotor nerve, trochlear nerve, and abducens nerve. …

*Some of the terminology explanations that mention "dispersion" are listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

Japanese:

…これに対し，運動方向と逆の作用をもつ筋群(上記の場合は右眼の内直筋と左眼の外直筋)を拮抗筋という。眼球の非共同運動には輻輳（ふくそう）convergence(収斂（しゆうれん）ともいう)と開散divergence(発散ともいう)の2型がある。輻輳は眼前の一点に視線を集中させる機能で，ふつう両眼の内直筋の収縮によって行われる。…