This book challenges scientific and philosophical orthodoxies about space, time, and perception by grounding these concepts in our ordinary experience of light and in the unassailable certainty of death. Taking our relation to our own body as the foundation for exploring vision and its reach to distant objects, it shows that light and death—understood experientially and existentially rather than as physical phenomena—play constitutive roles in shaping human experience and in what we regard as objective knowledge, both empirical and mathematical. In addressing these themes, the book engages contemporary debates in the philosophy of perception, mathematics, physics, and time. While written in appreciation of science and its achievements, the book argues that crucial aspects of vision, space, and time call for analysis that goes beyond the scientific domain. Emerging from the conviction that the world is the world as we experience it, the book nonetheless offers a defense of realism—though a distinctive form articulated within its own framework.