Range-extending system and spatial filter for enhancing hartmann-shack images and associated methods

A method for measuring aberration in an optical system comprising the steps of:

• providing a calibration matrix containing a two-dimensional position of a reference centroid and a positional relationship between the reference centroids;
• focusing a wavefront emanating from an optical system onto a lenslet array, the output from the lenslet array comprising a test matrix containing a two-dimensional position of optical system spot centroids;
• calculating a positional relationship between the optical system spot centroids and populating the test matrix with the calculated positional relationships;
• identifying one known relationship between one reference centroid and the centroid of one eye spot;
• and
• determining at least some of the remaining relationships between the reference centroids and the eye spot centroids, the determined relationships providing a measure indicative of the eye aberration.

A system for measuring aberration in an eye comprising:

• a lenslet array positioned to receive a wavefront, an output thereof upon receiving collimated light comprising a grid formed by edges of the lenslets and a reference spot having a centroid in at least some members of the grid, each reference spot having a known relationship to the grid member and a centroid, an output thereof upon receiving an aberrated wavefront comprising the grid and an eye spot having a centroid in at least some members of the grid;
• a sensor for receiving the lenslet array output;
• a processor in data-receiving communication with the sensor;
• and
• software means resident on the processor for:
• determining a position of each reference centroid and each eye spot centroid and a relationship between the reference centroids and between the eye spot centroids;
• identifying one known relationship between one reference centroid and one eye spot centroid;
• and
• determining at least some of the remaining relationships between the reference centroids and the eye spot centroids, the determined relationships providing a measure indicative of the eye aberration.

A software package for calculating aberration from data collected from an optical system comprising:

• a routine for reading a predetermined calibration matrix from a storage unit, the calibration matrix containing a two-dimensional position of a reference centroid and a positional relationship between the reference centroids;
• a routine for transforming output from a lenslet array, the output from an aberrated optical system, into a test matrix containing a two-dimensional position of optical system spot centroids;
• a routine for calculating a positional relationship between the optical system spot centroids and for populating the test matrix with the calculated positional relationships;
• a routine for identifying one known relationship between one reference centroid and the centroid of one eye spot;
• and
• a routine for determining at least some of the remaining relationships between the reference centroids and the eye spot centroids, the determined relationships providing a measure indicative of the eye aberration.