Some Tests of Night and Day Vision

TLDR: In this paper, the authors introduce some tests of night and day vision which, though devised for a special purpose, are potentially useful in a much wider variety of applications and are implemented via specially developed slides to be used in a commercial vision test instrument.

Abstract: : The report introduces some tests of night and day vision which, though devised for a special purpose, are potentially useful in a much wider variety of applications. The tests are mostly of binocular visual acuity for far vision, measured either during the course of dark adaption or after adaption to various light levels has been completed. In addition, a special form recognition test has been developed to investigate the relationship between visual acuity data and the visibility of a 'real-life' shape, namely, the silhouette of a man. The test are implemented via specially developed slides to be used in a commercial vision test instrument. The latter has been adapted to provide a range of discrete nighttime and daytime light levels (through the use of neutral density filters). Unlike the slides normally provided with this instrument, those specially developd cover a wide range of contrast values. Thus, acuity may be tested over a wide range of contrasts at each of the nighttime and daytime light levels. (Author)