Eye protection from liquids and flying debris is provided by safety glasses. Because clear glasses do not block light, they are ideal for wearing indoors or when changing lighting conditions. When working outdoors or in strong light, dark lenses reduce light, glare, and eye strain. Amber (or yellow) lenses improve contrast in low-light situations by filtering haze and blue light. Infrared light produced by welding is filtered by green lenses. Magnification is included into readers to make reading, inspection, and fine detail work easier. Over-the-glasses (OTG) frames are designed to fit over most prescription eyewear, allowing workers to use their own glasses.