title: Psychophysical evidence for losses in rod sensitivity in the aging visual system.
abstract: Rod sensitivity was measured with a criterion-free psychophysical method at 10 deg in the horizontal meridian of the nasal field of the left eye on 26 young (mean age, 24.1 yr) and 14 older (mean age 72.6 yr) observers in good ocular health. A 1 deg, 90 msec stimulus was delivered by means of a free-viewing optical system under computer control. Stimulus wavelengths were chosen to have either significant (406 nm) or minimal (560 nm) absorption by the older lens. After correction for senile miosis and lens density, 0.39 log unit higher thresholds for the older observers remained and are interpreted as being due to neural factors.
authors.affiliation: Department of Psychology, Syracuse University, NY 13244-2340, USA. jfsturr@mailbox.syr.edu
authors.forename: J F
authors.initials: JF
authors.lastname: Sturr
authors.forename: L
authors.initials: L
authors.lastname: Zhang
authors.forename: H A
authors.initials: HA
authors.lastname: Taub
authors.forename: D J
authors.initials: DJ
authors.lastname: Hannon
authors.forename: M M
authors.initials: MM
authors.lastname: Jackowski
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging; D000704:Analysis of Variance; D005260:Female; D006801:Humans; D007908:Lens, Crystalline / Q000502:physiology; D008297:Male; D008875:Middle Aged; D017948:Retinal Rod Photoreceptor Cells / Q000502:physiology*; D012684:Sensory Thresholds / Q000502:physiology*; D012737:Sex Factors