Individual red blood cells carry oxygen through microscopic vessels that determine whether tissues thrive or deteriorate, yet scientists have lacked precise tools to observe this fundamental life process in real time. This technological gap has limited our understanding of how oxygen delivery fails in diseases ranging from stroke to diabetes. A breakthrough imaging technique now enables researchers to track single red blood cells as they navigate three-dimensional vessel networks, measuring both their movement patterns and oxygen content without requiring injected contrast agents. The super-resolution functional photoacoustic microscopy system uses dual-wavelength light excitation to generate acoustic signals that reveal cellular-level hemodynamics with unprecedented clarity. In laboratory studies with live mice, the technology captured how oxygen distribution reorganizes across microvascular networks immediately following experimentally induced single-vessel strokes. The method achieved imaging resolution comparable to established two-photon microscopy while adding quantitative oxygen measurements that previous techniques could not provide. This represents a significant methodological advance for microvascular research, as traditional imaging approaches either lack sufficient resolution to track individual cells or require fluorescent labels that can interfere with normal physiology. The ability to monitor label-free oxygen dynamics at the single-cell level opens new research possibilities for understanding how microvascular dysfunction contributes to aging, neurodegenerative diseases, and metabolic disorders. While the current demonstrations focus on animal models, the non-invasive nature of photoacoustic imaging suggests potential future applications in human diagnostics. The technology's capacity to bridge molecular-level oxygen measurements with tissue-scale hemodynamics could accelerate development of treatments targeting microvascular health.