Microsaccades and pupil size change are two oculomotor responses regulated by higher-level cognitive processes, for example, salience detection. Recent evidence suggests that the superior colliculi (SC) are involved in salience encoding and are also important brain structures in microsaccades generation and the pupil psychosensory response (Engbert and Kliegl, 2003; White et al., 2017; Wang et al., 2012). The involvement of SC may suggest that there are coordinated responses or interactions between microsaccade and pupillary response. Thus, we used data from an oddball test to study these two responses to salient oddball stimuli, non-salient control stimuli, and alter-luminant stimuli across the human lifespan. Study one investigated whether there exists coordinated responses of both microsaccades and pupils induced by the stimuli or not. The results showed that saliency induced coordinated orienting responses on both microsaccades and pupils, while the alter-luminant stimuli induced an autonomic reflex in pupils only. Because evidence suggests that microsaccades would interfere with later oculomotor responses and visual bursts in SC (Zuber and Stark, 1966; Hafed and Krauzlis, 2010), we in study two proposed that the presence of pre-trial baseline microsaccades would influence later pupillary responses in the SC-involved orienting responses. However, the results showed strong suppression in pupil dilation in both control and alter-luminant conditions but barely any influence in the salient condition. We thus proposed a possible mechanism of such microsaccades-pupil interaction that the microsaccades might suppress a brain structure upstream of the SC in the sympathetic pathway to influence pupil dilation in control and alter-luminant condition while leaving the orienting response intact. In both studies, age was a significant influencer.