In this International Year of Light, it is particularly appropriate to review the historical concept of what is light and the controversies surrounding the extent of the visible spectrum. Today we ...

Classically, light can be thought of in two ways: either as a particle or a wave. But what is it really? Well, the ‘observer effect’ makes that question kind of difficult to answer. So before we get ...

What is blue light? “All the light we see is made up of different wavelengths of light,” says Vivienne Sinh Hau, MD, an ophthalmologist at Kaiser Permanente in Riverside, California. “Certain ...

Light is well known to exhibit both wave-like and particle-like properties, as imaged here in this 2015 photograph. What's less well appreciated is that matter particles also exhibit those wave-like ...

Women's Health may earn commission from the links on this page, but we only feature products we believe in. Why Trust Us? At the simplest level, different colors of light have different wavelengths.

Blue light usually comes from the sun but also from digital screens and LED lights. Some experts believe artificial sources may be causing eye damage in humans, but animal studies are inconclusive.

Why is light affected by gravity if photons are massless? originally appeared on Quora: the place to gain and share knowledge, empowering people to learn from others and better understand the world.

Light-years make measuring astronomical distances much more manageable. When you purchase through links on our site, we may earn an affiliate commission. Here’s how it works. A light-year is a ...

If your social media feed is full of glowing red face masks and crimson saunas, you're not alone. Lately, it seems like everyone is obsessed with red light therapy and hailing it for its various ...

Red light therapy (RLT) is a therapeutic technique that uses low-level wavelengths of red light to help treat skin conditions such as wrinkles and psoriasis. Though the treatment seems promising, more ...

One of the most common questions I get asked as a beauty editor is what at-home beauty treatments are actually worth it. My answer? Red light therapy. There’s a reason you’ll find red light devices in ...