Eye motion poses a significant challenge in efficiently capturing high-resolution retinal images and efficiently delivering cell-targeted photostimulation using adaptive optics (AO). In this manuscript, we present a solution to optically correct retinal movements in real-time by integrating galvanometer mirrors, pupil-conjugated, in an AO Flood-illumination ophthalmoscope (AO-FIO). Our approach involved using AO-FIO images to measure retinal motion with sub-pixel precision and correct it in a closed-loop fashion and at 200Hz. Through the proposed closed-loop optical stabilization, we achieved a notable reduction in retinal motion from 25 µm rms to 1.2µm rms. This performance was achieved 88% of the time over more than 40s without any decay of precision. Moreover, optical stabilization at this high precision was possible using images acquired in both photoreceptor and nerve fiber layers. To our knowledge, this level of precision and efficiency surpasses any previously reported method.