Simple Hartmann test data interpretation for ophthalmic lenses

Abstract

This article describes a simple Hartmann test data interpretation that can be used to evaluate the performance of ophthalmic lenses. Considering each spot of the Hartmann pattern such as a single test ray, using simple ray tracing analysis, it is possible to calculate the power values from the lens under test at the point corresponding with each spot. The values obtained by this procedure are used to plot the power distribution map of the entire lens. We present the results obtained applying this method with single vision, bifocal, and progressive lenses.

Measurement of spherical and cylindrical power in ophthalmic lenses based in the change of lateral amplification

“…Finally , Hartmann test [13][14][15][16][17][18] is the most used method for the characterization of ophthalmic lenses due to the high accuracy on its measurements. There are many variations to this test but basically uses a plate of holes equally distributed commonly illuminated with a laser source and analyzes the a) Electronic mail: palomascbtis@gmail.com.…”

Accurate and precise optical testing with a differential Hartmann wavefront sensor

“…The tolerance on the nominal power of the reference lenses is unknown but is assumed to be less than the Ϯ0.06 diopter manufacturing tolerance on single-vision ophthalmic lenses. 6 The nonzero P values in Table 1 may indicate that the Hartmann plate was not accurately aligned with the center of the lens. The nonzero C values may indicate an angular misalignment of the ref- erence wavefront and the optical axis of the lens.…”

“…Accurate determination of the characteristics, however, usually requires detailed knowledge of the incident reference wavefront and of the location of some of the cardinal planes. 6 In this paper, we describe a differential Hartmann wavefront sensor that provides accurate, precise, and simple measurements of the characteristics of an optical system. This is achieved by combining transverse aberrations measured in two planes that are separated by an accurately and a precisely known distance.…”

“…The optical characteristics of systems that transmit or reflect light can be determined using a variety of techniques, including Hartmann [1][2][3][4][5][6][7] (H) and ShackHartmann 8 -10 (S-H) wavefront sensors. S-H sensors, for example, are widely used to measure and control the effect of atmospheric turbulence in astronomical adaptive optics, as they are compatible with low light intensities and can operate at sampling rates of several kHz.…”

“…In systems that use a collimated reference wavefront, this assumption requires that the locations of the second principal plane of the optic and the active surface of the detector are known accurately. 6 While the second requirement may be reasonable, the first will limit the applicability and accuracy of this technique. This calculation would be even more problematic if the reference wavefront was not collimated, as the plane from which l should be measured cannot a priori be well defined.…”