How does perceptual experience make us knowledgeable about the world? In this book Nadja El Kassar argues that an informed answer requires a novel theory of perception: perceptual experience involves conceptual capacities and consists in a relation between a perceiver and the world. Contemporary theories of perception disagree about the role of content and conceptual capacities in perceptual experience. In her analysis El Kassar scrutinizes the arguments of conceptualist and relationist theories, thereby exposing their limitations for explaining the epistemic role of perceptual experience. Against this background she develops her novel theory of epistemically significant perception. Her theory improves on current accounts by encompassing both the epistemic role of perceptual experiences and its perceptual character. Central claims of her theory receive additional support from work in vision science, making this book an original contribution to the philosophy of perception.