ver.gence
n.（名词）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.光折射度数：一对光线聚合或发散的计量单位，定义为参照点与光线交叉点之间距离的倒数The inward or outward turning of one or both eyes that occurs when focusing on an object.注视点：目光集中在一个物体上时，单颗或两颗眼珠向内或向外的转动
