Employees must wear appropriate eye or face protection when exposed to hazards such as flying particles, molten metal, liquid chemicals, radiation, or potentially injurious light. Eye protection must meet ANSI Z87.1 standards and be selected based on the specific hazard. Safety glasses with side shields provide protection against flying particles from grinding, cutting, or chipping operations. Welding helmets or face shields must be used when welding or plasma cutting to protect against ultraviolet and infrared radiation and flying sparks. Chemical splash goggles must be worn when handling caustic or corrosive materials, and must completely encircle the eye area to prevent liquid from running behind the lens. Laser safety glasses must be worn when working with laser equipment and must be rated for the specific wavelength being used. Impact-resistant lenses are required in high-impact environments where particles travel at high velocity. Corrective lenses can be combined with protective equipment for employees who require vision correction. Hard contact lenses and regular eyeglasses are not acceptable substitutes for protective eyewear. Employees must be trained on hazard recognition and selection of appropriate protective equipment. Eye protection must be inspected regularly and replaced if cracked, pitted, or damaged. All employees must have access to emergency eyewash and shower facilities if corrosive materials are used on the job site.