| pubmed-article:7780273 | pubmed:abstractText | Basic investigations in the field of adaptation luminance were carried out using Holladay's visual threshold criterion. The connection between adaptation luminance LA, illumination at the spot in the eye EB1 and the angle of glare theta is LA = 9.2 x EB1 x theta -2 LA in cd/m2, Eb1 in 1x, theta in degrees. In most cases the investigations of adaptation luminance were also carried out under conditions of fixed view and static visual tasks. It is however, important to take into account the dynamic visual task and the adaptation process by determining the adaptation luminance, but very few measurements have been carried out under these conditions. For the results represented here the visual threshold was replaced by the readaptation time necessary for perception of movement direction of a striped pattern (dynamic) and with the idea of also comparing the perception of the slot location in a ring in the Landolt rings (static). The method of investigations was as follows: The subject adapts to the inhomogeneous field of luminance for which the adaptation luminance must be determined. Then in a dark surrounding field for comparison, the visual task is offered, and the readaptation time necessary for the fulfillment of the visual task is measured. This procedure is repeated with a homogeneous field of luminance. The luminance of a homogeneous field is equal to the adaptation luminance. If the readaptation times are equal, the inhomogeneous distribution of luminance has the adaptation luminance LA. The important difference in comparison to previous investigations is the inclusion of dynamic components (readaptation time and dynamic visual task).(ABSTRACT TRUNCATED AT 250 WORDS) | lld:pubmed |
