| trial safety equipment is used to reduce the risk | | | | protection in outside activities from flying debris |
| of injury, loss and danger to persons, property or | | | | and ultraviolet light. |
| the environment in any facility or place involving | | | | Scratch-resistant coatings can be applied to most |
| the manufacturing, producing and processing of | | | | plastic lenses giving them similar scratch resistance |
| goods or merchandise. All around the clock safety | | | | to glass. Hydrophobic coatings designed to ease |
| of the workers and the industrial safety | | | | cleaning are also available, as are anti-reflective |
| equipment should be ensured by the employer | | | | coatings intended to improve night vision and |
| and the employee. | | | | make the wearer's eyes more visible. |
| Not all glasses are designed solely for vision | | | | Earmuffs are foam filled cushions and pivoting ear |
| correction, but rather for protection, viewing visual | | | | cups provide a snug, comfortable fit. Earmuffs are |
| information (such as stereoscopy) or simply just | | | | objects designed to cover a person's ears for |
| for aesthetic or fashion values. Safety glasses are | | | | protection resembling the headphone. They |
| a kind of eye protection against flying debris or | | | | consist of a thermoplastic or metal headband that |
| against visible and near visible light or radiation. | | | | fits over the top of the head, and a pad at each |
| Sunglasses allow better vision in bright daylight, | | | | end, to cover the external ears. They come in |
| and may protect against damage from high levels | | | | two basic kinds: Thermal earmuffs: the original |
| of ultraviolet light. Industrial Safety glasses are a | | | | type, worn in winter to keep a person's ears |
| kind of eye protection against flying debris or | | | | warm. |
| against visible and near visible light or radiation. | | | | Acoustic earmuffs, also known as ear defenders: |
| Eyeglass frames are commonly made from | | | | cups lined with sound-deadening material, like |
| metal, horn or plastic. Lenses were originally made | | | | thermal earmuffs and headphones in appearance, |
| from glass, but many are now made from | | | | which are worn as hearing protection. These may |
| various types of plastic, including CR-39 or | | | | be carried on a head-band or clipped onto the |
| polycarbonate. These materials reduce the danger | | | | sides of a hard hat, for easy use on construction |
| of breakage and weigh less than glass lenses. | | | | sites. Some manufacturers combine headphones |
| Some plastics also have more advantageous | | | | with ear defenders, allowing the wearer to listen |
| optical properties than glass, such as better | | | | to music, communication or other audio source |
| transmission of visible light and greater absorption | | | | and also enjoy protection or isolation from |
| of ultraviolet light. Some plastics have a greater | | | | ambient noise. Acoustic earmuffs were created in |
| index of refraction than most types of glass; this | | | | Italy in 1982. The advantages of earmuffs over |
| is useful in the making of corrective lenses shaped | | | | earplugs are: Less attenuation variability among |
| to correct various vision abnormalities such as | | | | users, designed so that one size fits most head |
| myopia, allowing thinner lenses for a given | | | | sizes, not easily misplaced or lost, may be worn |
| prescription. Nowadays safety glasses can be | | | | with minor ear infections and can be quickly |
| combined with sun glasses, allowing for eye | | | | placed over and removed from your ears. |