We have built a biomorphic micro visual sensor equipped with a mechanical scanning system. The sensor is inspired by the structure of the fly's compound eye which was found to possess a unique muscle and tendon actuation system for its scanning retina. The improvement in micro-opto-electro-mechanical systems encourages the design of reliable, efficient and integrated smart visual sensors for robotic applications in particular for the autonomous, visually-guided navigation of mobile robots. We have verified the effect of retinal scanning for a robotic visual system through the construction of a large-scale prototype at the millimeter-scale. The performance of a newly fabricated HEMS prototype whose size approaches the order of the insects' compound eyes is then evaluated in comparison with that of the large-scale prototype. The micro-sized visual sensor is composed of a scanning microlens array (120[μm] in lens diameter) and a photo-diode array. The actuation of the microlens array induces a rotation of the visual axes. According to the principle of retinal scanning, the micro-sensor is able to retrieve the local angular velocity with enhanced reliability.