This paper discusses a counterexample to the thesis that visual experience is cognitively impenetrable. My central claim is that sometimes visual experience is influenced by the perceiver’s beliefs, rendering her experience’s representational content indeterminate. After discussing other examples of cognitive penetrability, I focus on a certain kind of visual experience— that is, an experience that occurs under radically nonstandard conditions—and show that it may have indeterminate content, particularly with respect to low-level properties such as colors and shapes. I then explain (...) how this indeterminacy depends on the perceiver’s beliefs or thoughts. Finally, I attempt to generalize the case and show how other sorts of visual experiences can also be penetrated by beliefs and, hence, be indeterminate. (shrink)