[Measuring the level of tonic accomodation as a function of wavelength].
OBJECTIVE
Tonic accommodation contributes to the refractive state of the human eye in the absence of any visual stimulation. As the power of the eye, tonic accommodation level should be a function of wavelength and its variation should constitute a measure of longitudinal chromatic aberration of the eye.


METHODS
The level of tonic accommodation was measured with a vernier optometer on a sample of 10 subjects (21-39 years). Five monochromatic filters of wavelengths 450, 486, 550, 600, 656 nm have been used.


RESULTS
Results show a tonic accommodation variation with wavelength. The sample mean of longitudinal chromatic aberration (left eye) resulting from the variation of tonic accommodation as a function of wavelength is 1.42 +/- 0.08 D between 450 and 656 nm and 0.96 +/- 0.06 D between 486 and 656 nm.


CONCLUSIONS
These results fit the predictions from theorical models and question previous results.
Dechriste
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S
Université de Montréal, Laboratoire d'Optique physiologique, Ecole d'Optométrie, Québec, Canada.
Simonet
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D000065:Accommodation, Ocular; D000328:Adult; D006801:Humans; D008027:Light; D009907:Optometry / Q000295:instrumentation / Q000379:methods*; D012016:Reference Values
Mesure du niveau d'accommodation tonique en fonction de la longueur d'onde.