Bayesian model of Snellen visual acuity
نویسندگان
چکیده
منابع مشابه
Bayesian model of Snellen visual acuity.
A Bayesian model of Snellen visual acuity (VA) has been developed that, as far as we know, is the first one that includes the three main stages of VA: (1) optical degradations, (2) neural image representation and contrast thresholding, and (3) character recognition. The retinal image of a Snellen test chart is obtained from experimental wave-aberration data. Then a subband image decomposition w...
متن کامل[Snellen visual acuity evaluation].
PURPOSE To evaluate the visual acuity (VA) measurement by Snellen chart at three main Ophthalmology centers in Curitiba, compare these measurements with a computerized method for calibrating VA and also with the standard theory developed by Hermann Snellen. METHODS Descriptive study including 15 Ophthalmology clinics and a computerized method to measure the VA. Using a tape measure and a cali...
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The effect of artificially induced image defocusing on visual acuities (VAs) measured by spatial frequency sweep pattern reversal visual evoked response (SPVER) and Snellen measurement was studied in six normal subjects. The steady-state SPVER was recorded using vertical gratings of 10 different spatial frequencies ranging from 0.52 to 30.36 c/deg. The SPVER acuity was compared with Snellen acu...
متن کاملExperimental validation of a Bayesian model of visual acuity.
Based on standard procedures used in optometry clinics, we compare measurements of visual acuity for 10 subjects (11 eyes tested) in the presence of natural ocular aberrations and different degrees of induced defocus, with the predictions given by a Bayesian model customized with aberrometric data of the eye. The absolute predictions of the model, without any adjustment, show good agreement wit...
متن کاملBeyond snellen acuity: the assessment of visual function after refractive surgery.
T HE GOAL of refractive surgery is to improve unaided vision in ametropic patients without the aid of spectacles and contact lenses. Refraction for the prescription of these appliances has traditionally been based on high-contrast distance visual acuity using Snellen charts. It is under such conditions that residual spherocylindrical refractive error and visual acuity following refractive surge...
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ژورنال
عنوان ژورنال: Journal of the Optical Society of America A
سال: 2003
ISSN: 1084-7529,1520-8532
DOI: 10.1364/josaa.20.001371