In optics, vergence is the angle formed by rays of light that are not perfectly parallel to one another. Rays that move closer to the optical axis as they propagate are said to be converging, while rays that move away from the axis are diverging.
In optics, vergence is the angular difference among light beams not perfectly aligned. Converging rays are those that get closer to the optical axis during propagation, whereas diverging rays move away from it.