vergence

詳細解釋：

ver.gence

n.（名詞）
A measure of the convergence or divergence of a pair of light rays, defined as the reciprocal of the distance between a point of reference and the point at which the rays intersect.
光折射度數：一對光線聚合或發散的計量單位，定義為參照點與光線交叉點之間距離的倒數
The inward or outward turning of one or both eyes that occurs when focusing on an object.
注視點：目光集中在一個物體上時，單顆或兩顆眼珠向內或向外的轉動