TY  - JOUR
PY  - 1995//
TI  - The Freiburg Vision Test. Automated determination of visual acuity
JO  - Ophthalmologe : Zeitschrift der Deutschen Ophthalmologischen Gesellschaft
A1  - Bach, M.
SP  - 174
EP  - 178
VL  - 92
IS  - 2
N2  - 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>
LA  - de
SN  - 0941-293X
UR  - http://dx.doi.org/
ID  - ref1
ER  -