Spectral efficiency across the life span: flicker photometry and brightness matching.

J. M. Kraft, John S Werner

Research output: Contribution to journalArticlepeer-review

35 Scopus citations


Spectral efficiency functions were measured for 50 color-normal observers (aged 19-85 years) by means of heterochromatic flicker photometry (HFP) and heterochromatic brightness matching (HBM). Foveally viewed, circular, 1.2 degrees-diameter stimuli were presented as 3-s flashes (50% duty cycle) in Maxwellian view. Monochromatic lights (420-700 nm; 16 wavelengths) were equated to a 100-Td (trolands), broadband white standard in both procedures. In both HFP and HBM, average sensitivity (specified at the cornea) decreased at short wavelengths with increasing age, consistent with age-related increases in the density of the ocular media. The short-wavelength HBM decline was of lower magnitude than the HFP decline. HFP data were modeled by a weighted additive combination of long- and middle-wavelength-cone inputs and density spectra of the ocular media and macular pigment. HBM data were analyzed with an upper envelope of additive and subtractive combinations of log-transformed cone absorption functions. These analyses indicated that HBM sensitivity, specified at the retina by correction for estimated lens and macular pigment density, increased with age in an approximately wavelength-independent manner over a broad range from 420 to 560 nm.

Original languageEnglish (US)
Pages (from-to)1213-1221
Number of pages9
JournalJournal of the Optical Society of America. A, Optics and image science
Issue number4
StatePublished - Apr 1994
Externally publishedYes

ASJC Scopus subject areas

  • Medicine(all)


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