Acceleration characteristics of human ocular accommodation.
Position and velocity of accommodation are known to increase with stimulus magnitude, however, little is known about acceleration properties. We investigated three acceleration properties: peak acceleration, time-to-peak acceleration and total duration of acceleration to step changes in defocus. Peak velocity and total duration of acceleration increased with response magnitude. Peak acceleration and time-to-peak acceleration remained independent of response magnitude. Independent first-order and second-order dynamic components of accommodation demonstrate that neural control of accommodation has an initial open-loop component that is independent of response magnitude and a closed-loop component that increases with response magnitude.
Bharadwaj
Shrikant R
SR
Vision Science Group, School of Optometry, University of California at Berkeley, 512 Minor Hall, Berkeley, CA 94720-2020, USA.
Schor
Clifton M
CM
D000065:Accommodation, Ocular / Q000502:physiology*; D000328:Adult; D003290:Convergence, Ocular / Q000502:physiology; D006801:Humans; D009801:Oculomotor Muscles / Q000502:physiology*; D010775:Photic Stimulation