Stimuli characteristics ha a decisive role in our perception and cognition. In the present study, we aimed to evaluate the effects of dimension of stimuli, two-dimensional (2D) versus three-dimensional (3D), on perception and working memory. In the first experiment, using the method of eye tracking, a higher blink rate, pupil size, and the number of saccade for three compared to 2D stimuli revealed a higher perceptual demand of 3D stimuli. In the second experiment, visual search task shows a higher response time for 3D stimuli and an equal performance with 2- and 3D stimuli in spatial working memory task. In the third experiment, four working memory tasks with high and low cognitive and perceptual load revealed 3D stimuli are memorized better in the both low and high load of working memory. We can conclude that 3D stimulus, compared 2D, imposes a higher load on perceptual system, but it is memorized better. It could be concluded that the phenomenon of filtering should occur in the early perceptual system for preventing overload.