@article{ref1,
title="The Freiburg Vision Test. Automated determination of visual acuity",
journal="Ophthalmologe : Zeitschrift der Deutschen Ophthalmologischen Gesellschaft",
year="1995",
author="Bach, M.",
volume="92",
number="2",
pages="174-178",
abstract="The Freiburg Visual Acuity Test is an automatic computerized procedure for self-administered measurement of visual acuity. Landolt-Cs are presented on a monitor in one of eight orientations. The subject presses one of eight buttons, which are spatially arranged according to the eight possible positions of the Landolt-C's gap. To estimate the acuity threshold, a best-PEST procedure is employed, assuming a psychometric function with a constant slope on a logarithmic acuity scale. The discreetness artifacts in computer monitors limit the presentation of small stimuli. By anti-aliasing (smoothing of contours by gray-shading), the spatial resolution was improved by a factor of four, such that the shape of Landolt-Cs with oblique gaps is adequate and visual acuities from 0.06 up to 3.6 can be tested at a distance of 5 m.<p /><p>Language: de</p>",
language="de",
issn="0941-293X",
doi="",
url="http://dx.doi.org/"
}