Results 251 to 260 of about 1,757,364 (306)

Contrast sensitivity

Ophthalmology Clinics of North America, 2003
Spatial contrast is a physical dimension referring to the light-dark transition of a border or an edge in an image that delineates the existence of a pattern or an object. Contrast sensitivity refers to a measure of how much contrast a person requires to see a target.
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Contrast Sensitivity and Glaucoma

Journal of Glaucoma, 2019
Spatial contrast sensitivity decline occurs in different types and stages of glaucoma. In this short review we discuss methods of assessing contrast sensitivity, the role of contrast sensitivity in the pathogenesis of glaucoma and its practical application in clinical practice.
Parul, Ichhpujani, Sahil, Thakur, George L, Spaeth   +2 more
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Evaluating contrast sensitivity

SPIE Proceedings, 2006
The problem for proper rendering of spatial frequencies in digital imaging applications is to establish the relative contrast sensitivity of observers at suprathreshold contrast levels in typical viewing environments. In an experimental study two methods of evaluating spatial contrast sensitivity were investigated, using targets of graded tonal ...
Saori Kitaguchi, Lindsay W. MacDonald, Stephen Westland   +2 more
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Contrast sensitivity in dyslexia

Visual Neuroscience, 1995
AbstractContrast sensitivity was determined for dyslexic and normal readers. When testing with temporally ramped (i.e. stimuli with gradual temporal onsets and offsets) gratings of 0.6, 4.0, and 12.0 cycles/deg, we found no difference in contrast sensitivity between dyslexic readers and controls.
Karen Gross-Glenn, Bernt C. Skottun, William Glenn, Alex Kushch, Robert Lingua, Mark Dunbar, Bonnie Jallad, Herbert A. Lubs, Bonnie Levin, Mark Rabin, Lesley A. Parke, Ranjan Duara   +11 more
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Contrast sensitivity of optokinetic nystagmus

Vision Research, 1991
To determine the threshold characteristics of optokinetic nystagmus (OKN), contrast thresholds for involuntary OKN were measured for gratings of different spatial frequency to yield an OKN-contrast sensitivity function (OKN-CSF). The OKN-CSF resembled an inverted U-shaped function with temporal-to-nasal and nasal-to-temporal movement yielding similar ...
L E, Leguire, B S, Zaff, S, Freeman, G L, Rogers, D L, Bremer, N, Wali   +5 more
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Contrast Sensitivity

Journal francais d'ophtalmologie, 1987
In some patients with neural or ophthalmological lesions, normal visual acuity co-exists with a significantly diminished ability to see larger objects. The converse may also occur. Based upon many years of academic research and some years of clinical application, spatial contrast sensitivity function appears to give the most general description ...
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Jogging and contrast sensitivity

Acta Ophthalmologica, 1988
Abstract. Threshold contrast sensitivity was measured using sinusoidal gratings with the method of increasing contrast both before and after jogging in fresh air. The mean contrast sensitivity of 11 subjects was higher after jogging at all three spatial frequencies studied (1, 6 and 19 c/deg). The differences were statistically significant. The effect
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Effect of Ibuprofen on Contrast Sensitivity

Optometry and Vision Science, 1992
ABSTRACT Therapeutic doses of ibuprofen (2‐4'‐isobutylphenylpropionic acid) have been shown to have many deleterious effects on the nervous system. However, visual disturbances have been reported in fewer than 1% of the patients taking recommended doses of ibuprofen.
W H, Ridder, A, Tomlinson
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Contrast sensitivity in radial keratotomy

Acta Ophthalmologica, 1991
Abstract In a prospective study, contrast sensitivity function was determined before and one month post‐surgery in 15 consecutive cases of radial keratotomy. The results obtained pre‐operatively were compared to those of an age‐matched, emmetropic reference group also comprising 15 persons. Three different test conditions were employed.
H, Olsen, J, Andersen
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CONTRAST SENSITIVITY IN MONOCULAR GLAUCOMA

Acta Ophthalmologica, 1983
The results of this selected group of glaucoma patients demonstrate that the effect of glaucoma on the contrast sensitivity can be assessed only after careful exclusion of all other causes for decrease in contrast sensitivity. Further development of methods is necessary.
L, Hyvärinen, J, Rovamo, P, Laurinen, J, Saarinen, R, Näsänen   +4 more
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