We examined the recently discovered phenomenon of Adaptation-Induced Blindness (AIB), inwhich highly visible gratings with gradual onset profiles become invisible after exposure to a rapidlyflickering grating, even at very high contrasts. Using very similar stimuli to those in the original AIBexperiment, we replicated the original effect across multiple contrast levels, with observers atchance in detecting the gradual onset stimuli at all contrasts. Then, using full-contrast target stimuliwith either abrupt or gradual onsets, we tested both the orientation tuning and interoculartransfer of AIB. If, as the original authors suggested, AIB were a high-level (perhaps parietallymediated) effect resulting from the ‘gating’ of awareness, we would not expect the effects of AIB tobe tuned to the adapting orientation, and the effect should transfer interocularly. Instead, we findthat AIB (which was present only for the gradual onset target stimuli) is both tightly orientation-tuned and shows absolutely no interocular transfer, consistent with a very early cortical locus