I'll be discussing the relevance of the phenomenon of inattentional blindness for Dretske's account of simple seeing. In his 2007 paper 'What Change Blindness Teaches' Dretske proposes a knowledge test for what a subject is conscious of, according to which you must be aware of x if you can see (and thereby know) that x is F. I will examine this test in the light of Chabris and Simons' 'invisible gorilla' experiment and suggest that reflection on this experiment calls into question some aspects of Dretske's discussion.