[Experience in contrast vision testing].

INTRODUCTION

Since July 2011 driving licensing in Germany requires contrast vision to be tested. Recommendations are available for testing under mesopic conditions only. This study is aimed to provide recommendations for photopic testing.

METHOD: 169 persons were tested both under mesopic (Mesotest) and photopic (Optovist) conditions.

RESULTS

With the Mesotest the setting without glare and the requirement to recognize contrast 1:5 or with glare contrast 1:23 proved to be suitable. With the Optovist visual acuity size 0.4 without and 0.25 with glare proved to be adequate, if the requirement is to recognize the limit of 5 %.

DISCUSSION: Not unexpectedly, there is no perfect congruence between the tests. We therefore recommend that the screening methods used in industrial medicine need to be sufficiently sensitive and specific, unfortunately this is met only by some of the conditions supplied with the instruments.