Stereopsis is the perception of depth through the differences between the two eye images (binocular depth cues). A substantial proportion of adults cannot process those cues correctly. In a recent experiment, stereoblind observers recovered stereopsis in a perceptual learning task in which binocular depth cues are mixed with monocular depth cues. Stereopsis was recovered durably so that observers could experience stereoscopic depth in 3D movie theatres and everyday life for the first time. We propose to investigate that phenomenon, to improve it, to use it for an amblyopia treatment and to localize the brain areas involved in stereopsis. Stereopsis recovery offers a unique opportunity to discover the neural correlates of stereopsis with fMRI (functional Magnetic Resonance Imaging): our first study can overcome current protocol limitations because two contrasting conditions can be now devised with exactly the same task and stimuli and only a perceptual difference (before and after stereopsis recovery). In study 2, we will first document whether stereopsis can be more easily recovered using action video games, which were shown surprisingly efficient in perceptual learning. Second, we investigate whether amblyopic observers, who suffer from a monocular cortical loss of visual acuity, can take advantage of stereopsis recovery. Amblyopic observers usually also suffer from stereoblindness. We anticipate that after being able to use both eyes simultaneously in a stereoscopic task (stereopsis recovery), the amblyopic eye acuity will increase. Finally, in study 3, we investigate how to maximize stereopsis recovery by addition of several kinds of monocular depth cues (perspective, shading, shadows or motion parallax). All together, these three studies will go a step beyond the current understanding of perceptual learning, stereopsis and amblyopia, and could provide an efficient cure for adult amblyopia, for which no treatment exists at the moment.