Sunglass

A sunglass is a piece of eyewear with tinted, darkened, or reflective lenses designed to protect the eyes from sunlight. Modern sunglasses shelter the eyes from bright visible light and ultraviolet radiation, reduce glare, and provide comfort in sunny conditions. Many sunglasses incorporate additional features such as polarized lenses to cut glare from smooth surfaces, mirror coatings to reflect light, and gradient or photochromic lenses that adapt to changing light.

Lenses are usually made from glass or plastic materials such as polycarbonate. Most sunglasses offer UV protection rated as UV400, blocking 99–100% of UVA and UVB rays. Polarized lenses filter glare but do not protect against all UV, so combining polarization with UV protection is common. Frames are built from metal, plastic, or composite materials and are selected for fit, durability, and style. In safety contexts, sunglasses may meet standards such as ANSI Z87.1 in the United States or EN 1836 in Europe, indicating impact resistance and UV protection.

Historically, sunglasses appeared in various forms in ancient cultures, but mass-market sunglasses emerged in the 20th century for aviation and sports, with fashion driving broader adoption. Brands and models popularized in the mid-1900s helped establish sunglasses as everyday wear and fashion accessories, alongside their protective function.

In usage, the plural form sunglasses is far more common than sunglass, which may refer to a single lens or be encountered primarily in older or specialized texts.