Snell is a term often associated with the Snell's law of refraction, which describes how light bends when it passes from one medium to another. This law is named after the Dutch astronomer Willebrord Snellius, who formulated it in the 17th century. The law states that the ratio of the sine of the angle of incidence to the sine of the angle of refraction is constant for any two media. In addition to its scientific context, "Snell" can also refer to Snell helmets, which are designed to meet safety standards for various sports. These helmets are tested for impact resistance and are crucial for protecting athletes in activities like cycling and motorsports.