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OBJECTIVE This study examined the temporal summation properties of the aging visual system under a wide range of background luminances. METHODS Contrast thresholds for 0.5 cpd gratings for 12 younger (mean age 20.6 years) and 12 older (mean age 71.6 years) observers in good ocular health were measured for 6 stimulus durations (from 10 to 1000 ms) under 4 background luminances (from 0.44 to 249.50 cd/m2). Two-alternative forced-choice staircase method was used. RESULTS We found significant main effects of age, background luminance, and stimulus duration on the contrast threshold. There were no age-related differences in the shape of the threshold-duration functions under all background luminances, although the shape changed significantly with background luminance. Age-related differences in contrast threshold were significant under the two lowest, but not under the two highest, background luminances. CONCLUSIONS Age-related alteration in visual sensitivity may be attributed to sensitivity (amplitude) losses but not to changes in temporal characteristics of the visual system.
L Zhang, and
J F Sturr
May 2008,
Optometry and vision science : official publication of the American Academy of Optometry,
L Zhang, and
J F Sturr
January 1981,
Vision research,
L Zhang, and
J F Sturr
June 1990,
Journal of the Optical Society of America. A, Optics and image science,
L Zhang, and
J F Sturr
July 1999,
Vision research,
L Zhang, and
J F Sturr
March 1984,
Perception & psychophysics,
L Zhang, and
J F Sturr
August 1994,
Vision research,
L Zhang, and
J F Sturr
July 2002,
Journal of the Optical Society of America. A, Optics, image science, and vision,
L Zhang, and
J F Sturr
January 2000,
Vision research,
L Zhang, and
J F Sturr
January 1988,
Vision research,
L Zhang, and
J F Sturr
February 1999,
Perceptual and motor skills,
