The phase of low frequency (4-7Hz, theta; 8-12Hz, alpha) brain oscillations modulate perceptual performance periodically over time. We hypothesize that not only the temporal dynamics of brain oscillations but also their spatial organization within the visual cortex have a functional role on perception. In a first experiment, human participants (n=15) performed a psychophysical task with simultaneous EEG recordings. Theta and alpha brain oscillations were induced by a peripheral disk oscillating in luminance (30s of inducer stimulus; 4, 6, 8 and 10Hz), while participants performed a low-contrast target detection task (50% detection). The targets were presented at random delays during the inducer presentation, at one of three possible eccentricities between a fixation cross and the inducer. EEG analyses showed that the disk induced complex brain oscillations, composed of the induced frequency and its first harmonic, in the visual cortex. We further showed that the inducer modulated detection performance periodically at each target position and frequency. Interestingly, the optimal phase for visual perception (maximal performance) shifted as a function of target eccentricities for 8 and 10Hz brain oscillations, with a respective propagation speed of 0.08 and 0.05 m/s. In a second experiment, participants (n=14) performed the same task, except that the inducer was a checkerboard annulus around fixation, pattern reversing at 10Hz. Similar to the first experiment, the optimal phase shifted as a function of distance from the annulus. Our results demonstrate that induced alpha oscillations are propagating across the human visual cortex, leading perceptual cycles to travel across the retinotopic space.