It’s wild to think people in the 1800s blamed the sun for everything from coughs to melancholy. Back then, they noticed that a sunny day could feel better, but they had no idea about photons or skin biology. The real shift began when scientists realized that light itself—its wavelength, intensity, and duration—could influence cells. That led to early phototherapy, using broad‑band lamps to treat rashes or neonatal jaundice. Then, when lasers came along in the 1960s, we got a source we could tune, focus, and control with micrometer precision. Now we can target specific chromophores in tissues, induce safe heat or reactive oxygen species, and guide cells to heal. It’s like turning the old “sun‑cure” myth into a science‑based, precision medicine tool that actually works. And the best part? Every time a laser beam helps a patient recover, it feels like a little nod to that ancient fire‑by‑the‑window wisdom, but with the glow of modern physics.