Range extending system and spatial filter

When the range of a wave face sensor unites the focus of a parallel beam with a small lens array, it is expanded and an output generates the grid formed of the edge of a small lens, and the reference spot in the component of this grid. Each standard centroid has the known relation and centroid to a grid component. The relation between standard centroids is determined. Subsequently, the wave face emitted from an eye can unite a focus with a small lens array, the output from a small lens array forms an eyespot with a grid and aberration there, and each eyespot has centroid. The relation between eyespot centroids is determined. One known relation between one standard centroid and the centroid of one eyespot is identified. Even if the last has few relations of the remainder between the above-mentioned standard centroid and the above-mentioned eyespot centroid, some are determined as it. This determined relation gives the index which shows the aberration of an eye.