Involuntary eye movements were recorded during threshold detection tasks under various experimental conditions. The data were analyzed for interdependencies between stimulus parameters, detection performance, and oculomotor behaviour. The data demonstrate that under certain conditions, saccadic parameters are adaptive to specific stimulus properties. Further, the data suggest that for stationary patterns with low spatial frequencies and for gratings flickering with high temporal frequencies, detection is facilitated considerably by the occurrence of a saccadic eye movement. These facilitation effects are consistent with the predictions of a theoretical model presented in a previous paper.