Results 51 to 60 of about 82 (67)
Optometry and Vision Science, 1985 Recent photographic studies have generated renewed interest in the optics of the retinoscopic (skiascopic) image. In photoretinoscopy the subject's eye is illuminated by a point source of light and the fundal image of this light at the plane of the subject's pupil is observed or photographed from a position near the source.
Howard C. Howland
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Optometry and Vision Science, 1987 The presence of significant refractive error and/or anisometropia can produce an irreversible decrease in visual function if not detected and treated at an early age. The general consensus is that the earlier a problem is detected, the easier the process of remediation.
R H, Duckman, B, Meyer
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Evaluation of Infant Accommodation Using Retinoscopy and Photoretinoscopy
Optometry and Vision Science, 2009 To compare PlusOptix PowerRefractor (PR) and Monocular Estimation Method (MEM) for measurement of infant accommodation and to assess the usefulness of applying individual calibration factors to PR data.Subjects were 41 infants aged 3 to 12 months. Accommodative response was measured by MEM and PR at 33 and 57 cm, acuity by Teller Acuity Cards, and ...
Gina Marangoni, Gabriel, Donald O, Mutti
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Theory of eccentric photorefraction (photoretinoscopy): astigmatic eyes
Journal of the Optical Society of America A, 1991 An optical analysis of eccentric photorefraction (photoretinoscopy) of astigmatic eyes is presented. The size and the angular tilt of the dark crescent appearing in the subject's pupil are derived as a function of five variables: the ametropia of the eye (Dsph, Dcyl, axis), the eccentricity of the flash, e, and the distance of the camera from the ...
W, Wesemann, A M, Norcia, D, Allen
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Vision Science and its Applications, 1999 Results from experimental animals have suggested that the retina can determine the amount and the sign of defocus at each location in the visual field to control the growth of the underlying sclera.
Anne Seidemann +3 more
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Measurement of Astigmatism by Automated Infrared Photoretinoscopy
Optometry and Vision Science, 1997 There are basically two possibilities to measure cylindrical refractive errors by eccentric photorefraction. The first is to determine the size and the tilt of the light crescent in the subject's pupil. Sphere, cylinder, and axis can be obtained from two pictures with the knife edge at two different orientations by using equations derived by Wesemann ...
F, Gekeler +3 more
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Three-dimensional reconstruction of surfaces by automated infrared photoretinoscopy
Vision Science and its Applications, 1997 A photoretinoscope with infrared light-emitting diodes (LED) operating simultaneously from different eccentricities creates an almost linear change in brightness across the pupillary meridian perpendicular to the knife edge (Schaeffel et al., 1993a).
Frank Schaeffel +2 more
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