@article{10.1167/iovs.15-18084, author = {Chung, Susana T. L. and Legge, Gordon E.}, title = "{Comparing the Shape of Contrast Sensitivity Functions for Normal and Low Vision}", journal = {Investigative Ophthalmology & Visual Science}, volume = {57}, number = {1}, pages = {198-207}, year = {2016}, month = {01}, abstract = "{ The contrast sensitivity function (CSF) provides a detailed description of an individual's spatial-pattern detection capability. We tested the hypothesis that the CSFs of people with low vision differ from a “normal” CSF only in their horizontal and vertical positions along the spatial frequency (SF) and contrast sensitivity (CS) axes. Contrast sensitivity for detecting horizontal sinewave gratings was measured with a two temporal-interval forced-choice staircase procedure, for a range of SFs spanning 5 to 6 octaves, for 20 low-vision observers and five adults with normal vision. An asymmetric parabolic function was used to fit the aggregate data of the normal-vision observers, yielding the “normal template.” Each of the 20 low-vision CSFs was fit in two ways, by using a shape-invariant version of the normal template (with the width parameters fixed) that was shifted along the log-SF and log-CS axes, and by an unconstrained asymmetric parabolic function (“free-fit”). The two fitting methods yielded values of the peak CS, the SF corresponding to peak CS, and the high cut-off SF that were highly correlated and in good agreement with each other. In addition, the width parameters of the low-vision CSFs were comparable with those of the normal template, implying that low-vision CSFs are similar in shape to the normal CSF. The excellent agreement of parameters estimated by the two fitting methods suggests that low-vision CSFs can be approximated by a normal CSF shifted along the log-SF and log-CS axes to account for the impaired acuity and contrast sensitivity. }", issn = {1552-5783}, doi = {10.1167/iovs.15-18084}, url = {https://doi.org/10.1167/iovs.15-18084}, eprint = {https://arvojournals.org/arvo/content\_public/journal/iovs/934840/i1552-5783-57-1-198.pdf}, }