Light-emitting diodes are front and center for many of our digital experiences. Every modern phone and tablet you look at uses LEDs in its display. It’s worth knowing how these work. In short, LEDs ...

They look otherworldly — like a Star Wars Stormtrooper’s helmet — and promise to give you clearer, smoother-looking skin. LED light masks are exactly what they sound like: devices illuminated by LED ...

Before we get into which products you should buy, there is much to learn about LED. When I first heard about light therapy as skincare, I thought it might be a fad. But forms of light therapy, also ...