Results 261 to 270 of about 26,550 (306)

Perceptual detectability of ocular accommodation microfluctuations

Journal of the Optical Society of America A, 1989
When the eye fixates a stationary stimulus, the power of the lens is known to change rapidly and continuously. Although the basic characteristics of this fluctuating activity are known and the influencing factors have been identified, their exact role in the control of accommodation is uncertain. It is thought that, for the fluctuations to be useful, a
B, Winn, W N, Charman, J R, Pugh, G, Heron, A S, Eadie   +4 more
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Ocular Accommodation in Human Infants

Optometry and Vision Science, 1983
The present longitudinal investigation evaluated the proficiency of the human ocular accommodation system during the 20-week period after birth. Fourteen human infants were tested at specific intervals during the age of 2 through 20 weeks. At each age the refractive state of the eyes during fixation of a vertical-striped, high-contrast stimulus pattern
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The Effect of Accommodation on Ocular Shape

Optometry and Vision Science, 2002
Ocular shape is altered in myopia, and accommodation during nearwork is a proposed risk factor for myopia. Using relative peripheral refractive error (RPRE), ocular shape was assessed before, during, and after a period of sustained nearwork to determine whether accommodation affects ocular shape.Measurements of RPRE at 30 degrees in the nasal visual ...
Terry W, Walker, Donald O, Mutti
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Arterial pulse modulates steady-state ocular accommodation

Current Eye Research, 1990
Rapid and continuous fluctuations in ocular focus are known to occur when the eye views a stationary target. The advent of high-speed infra-red optometers has established that these microfluctuations of ocular accommodation have two dominant components: low frequency of less than 0.6 Hz and high frequency between 1.0-2.3Hz.
B, Winn, J R, Pugh, B, Gilmartin, H, Owens   +3 more
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Ocular Accommodation, Personality, and Autonomic Balance

Optometry and Vision Science, 1983
The autonomic nervous system is made up of two subsystems: the parasympathetic (PNS) and the sympathetic (SNS). The balance between these systems regulates bodily functions during routine (PNS-dominant) and crisis (SNS-dominant) situations. It may also control visual accommodation: PNS activation for inward focus, and SNS activation for outward focus ...
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Accommodative Esotropia After Ocular and Head Injury

American Journal of Ophthalmology, 1990
Five children lost their ability for motor fusion after traumatic injury to either the eye or head. All patients had the onset of accommodative esotropia within two months of the traumatic episode. The ocular alignment of each child was controlled by the use of spectacles that corrected the accommodative requirements.
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Ocular Component Correlates of Tonic Accommodation

Ophthalmic and Visual Optics, 1992
Tonic accommodation (TA) and its adaptation have attracted considerable interest in recent years as putative risk factors for myopia (Ebenholtz, 1983) and TA is currently under investigation in prospective studies of adults (McBrien and Adams, 1989). TA has been widely studied as a function of refractive error. Maddock et al.
Donald O. Mutti, Karla Zadnik, Anthony J. Adams   +2 more
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Ocular accommodation in chickens: Corneal vs lenticular accommodation and effect of age

Vision Research, 1986
The avian accommodative response has long been suspected of having a corneal component resulting from contraction of a limbal extension of the ciliary muscle. Efforts to confirm the existence of such a mechanism have been sporadic and the results contradictory.
J G, Sivak, T E, Hildebrand, C G, Lebert, L M, Myshak, L A, Ryall   +4 more
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Role of ocular aberrations in dynamic accommodation control

Clinical and Experimental Optometry, 2009
Accommodation control is mediated by a number of cues, including blur,chromatic aberration and target proximity. Data from wavefront measurements have shown clear shifts in ocular aberrations during increasing accommodative demand, most notably a negative shift in spherical aberration. Work in adaptive optics, where aberrations have been corrected, has
Chin, Sem Sem, Hampson, Karen, Mallen, Edward A.H.   +2 more
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Modification of pattern reversal VERs by ocular accommodation

Vision Research, 1985
The amplitudes and implicit times of the P-1 component of monocular transient pattern VERs elicited by reversing checkerboard targets were measured in 6 conditions: (1) Ocular accommodation (Ao) elicited by minus power ophthalmic lenses; (2) Ao stimulated by minus lenses with the natural pupil of the test eye dilated and replaced by an artificial pupil;
J V, Lovasik, M, Spafford, M, Szymkiw
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