PMID- 15518204
OWN - NLM
STAT- MEDLINE
DCOM- 20050111
LR  - 20191210
IS  - 0952-5238 (Print)
IS  - 1469-8714 (Electronic)
IS  - 0952-5238 (Linking)
VI  - 21
IP  - 3
DP  - 2004 May-Jun
TI  - Long-term renormalization of chromatic mechanisms following cataract surgery.
PG  - 301-7
AB  - The optical density of the human crystalline lens progressively increases with 
      age, the greatest increase in the visible spectrum being at short wavelengths. 
      This produces a gradual shift in the spectral distribution of the light reaching 
      the retina, yet color appearance remains relatively stable across the life span, 
      implying that the visual system adapts to compensate for changes in spectral 
      sensitivity. We explored properties of this adaptive renormalization by measuring 
      changes in color appearance following cataract surgery. When the lens is removed, 
      cataract patients often report a large perceptual shift in color appearance that 
      can last for months. This change in color appearance was quantified for four 
      cataract patients (63-84 years) by determining the chromaticity of stimuli that 
      appeared achromatic before surgery, and at various intervals after surgery for up 
      to 1 year. Stimuli were presented on a calibrated CRT as 9.5-deg spots, with 3-s 
      duration and 3-s interstimulus intervals (ISIs). Chromaticity was adjusted by the 
      subjects in CIE L*a*b* color space with luminance fixed at 32 cd/m2, on a dark 
      background. We also estimated the optical density of the cataractous lens by 
      comparing absolute scotopic thresholds from 410 nm to 600 nm before and after 
      surgery. The results demonstrated that immediately following surgery there is a 
      large increase in the short-wave light reaching the retina, mainly below 500 nm. 
      The achromatic settings generally showed an initial large shift in the "yellow" 
      direction after surgery that gradually (but never fully) returned to the original 
      achromatic point before surgery. The shifts in the achromatic point occur over a 
      number of months and appear to occur independently of the fellow eye.
FAU - Delahunt, Peter B
AU  - Delahunt PB
AD  - Department of Ophthalmology and Section of Neurobiology, Physiology and Behavior, 
      University of California-Davis, 95817, USA. pbdelahunt@ucdavis.edu
FAU - Webster, Michael A
AU  - Webster MA
FAU - Ma, Lei
AU  - Ma L
FAU - Werner, John S
AU  - Werner JS
LA  - eng
GR  - R29 EY010834/EY/NEI NIH HHS/United States
GR  - R37 AG004058/AG/NIA NIH HHS/United States
GR  - R01 AG004058/AG/NIA NIH HHS/United States
GR  - EY10834/EY/NEI NIH HHS/United States
GR  - R37 AG004058-20/AG/NIA NIH HHS/United States
GR  - AG04058/AG/NIA NIH HHS/United States
GR  - R01 EY010834/EY/NEI NIH HHS/United States
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - England
TA  - Vis Neurosci
JT  - Visual neuroscience
JID - 8809466
SB  - IM
MH  - Adaptation, Ocular/physiology
MH  - *Cataract Extraction
MH  - Color Perception/*physiology
MH  - Discrimination, Psychological
MH  - Humans
MH  - Lens, Crystalline
MH  - Postoperative Period
MH  - Time Factors
MH  - Visual Perception/*physiology
PMC - PMC2633455
MID - NIHMS77324
EDAT- 2004/11/03 09:00
MHDA- 2005/01/12 09:00
PMCR- 2009/02/01
CRDT- 2004/11/03 09:00
PHST- 2004/11/03 09:00 [pubmed]
PHST- 2005/01/12 09:00 [medline]
PHST- 2004/11/03 09:00 [entrez]
PHST- 2009/02/01 00:00 [pmc-release]
AID - S0952523804213025 [pii]
AID - 10.1017/s0952523804213025 [doi]
PST - ppublish
SO  - Vis Neurosci. 2004 May-Jun;21(3):301-7. doi: 10.1017/s0952523804213025.