| Audiometric | An instrument for measuring hearing activity for pure tones of normally audible frequencies. Also called sonometer. |
| Base curve | The degree of curve in a lens – For instance, a lens with a 0-base curve would be flat, while a lens with 9-base curve would arc 9 degrees. |
| Blue light | Visible light – or radiation – in the blue (middle) portion of the color spectrum. Studies show that it may cause damage to the retina. |
| Bridge | The part of a spectacle frame that rests on the nose. |
| Cataracts | A condition in which the lens of the eye turns cloudy or opaque. As a result, light is not able to reach the retina and vision may diminish. |
| Communication Headset | A device (earplug or earmuff) designed primarily for communication. It may also provide or be used for hearing protection. |
| Compliance | Meeting or adherence to a given standard or rule – For instance, the ANSI Z87.1 standard applies to eye protection in the United States. |
| Cover Lens | An expendable pane of clear material that is used to protect a lens from damage. |
| Crown Protector | The portion of a protective device that rests on the top of the head. |
| Di-electric | A material that does not conduct electricity and can sustain an electric field. |
| Earplug | A hearing protector worn within the external ear canal (aural) or in the concha against the entrance to the external ear canal (semi-aural). |
| Earmuff | A hearing protector usually comprised of a headband and ear cups with a soft outer ring intended to fit snugly against the pinna (supra-aural) or the sides of the head around the pinna circumaural). |
| Face shield | Also known as a visor or window. It is a secondary protective device, commonly intended to shield an employee’s face. It should only be used in conjunction with primary eye protection. |
| Filter Lens | A lens that attenuates varying proportions of ultraviolet, visible, and infrared rays. |
| Glare | Uncomfortably bright light without hazardous levels of ultraviolet, visible, or infrared radiation. |
| Goggle | A protective device intended to fit the face and surround the eye. They provide protection against a variety of hazards, including impact and/or splash. |
| Hard coating | A coating process that makes materials, such as a lens, scratch-resistant. |
| Haze | Light that is not transmitted in a straight line. Excessive haze can cause blurring. |
| Headgear | A protective device, or part of one, that supports itself on the employee’s head. |
| Hearing Protector | A device that is worn to reduce the harmful erects of sound on the auditory system. |
| Lens | The transparent part of a protective device through which the employee sees. |
| Macular degeneration | An eye disorder that causes damage to the central part of the retina, called the macula. It is the main cause of blindness in people over 60. |
| Nanometer | One billionth of a meter. |
| Nylon | A strong, highly flexible, synthetic material that can be molded. It is commonly used to make frames on protective eyewear. |
| PCTG | Also known as Polycyclonexylenediamthylene Terepahthalate Glaycll. A durable, plastic material. It is an economical alternative to harder plastics. |
| PETG | Also known as Polyethylene Terepahthalate Glaycll. A durable, plastic material. It is an economical alternative to harder plastics. |
| Peripheral vision | The area of vision lying just outside the line of direct sight. |
| Photokeratitis | A temporary, but painful, sunburn of the cornea of the eye. It is caused by excessive exposure to UV-B radiation. |
| Plano Lens | A lens that does not incorporate a corrective prescription. |
| Polycarbonate | A family of thermoplastics that possess a high capacity for impact resistance |
| Polyethylene | A polymerized ethylene resin used in making tough, lightweight plastics, containers, and insulation. |
| Polypropionate | A durable, plastic material. It is an economical alternative to harder plastics. |
| PVC | Also known as Polyvinyl Chloride. A family of polymers derived from Vinyl Chloride. It is used to form molded objects. |
| Spectacle | Also known as safety glasses. A protective device designed to shield the employee’s eyes from a variety of hazards. |
| Side shields | A protective device, commonly attached to spectacles, which provides side protection to the eye. |
| Spatula Temples | A standard temple on a spectacle. Typically, it is made of the same material as the frame. |
| Temple | The sidepieces of a spectacle commonly attached to the front and generally extending behind the ear. It provides support for the spectacle. |
| Tinnitus | Buzzing, ringing, or other sounds in the ear caused by defect or damage to the auditory nerve. |
| Ultraviolet (UV) | An invisible band of light – or radiation – having a wavelength shorter than visible light. Studies show that it causes damage to the retina. |
| Unitary lens | A single-piece lens that covers both eyes. It provides a wide, unobstructed viewing area. |
| Universal Bridge | The nosepiece of a spectacle frame. It fits a wide variety of sizes and shapes. |
| Velveteen | A velvet-like nabbed fabric with a smooth, dense pile. |
| Vinyl | A family of soft and flexible, but tough plastics. It is commonly used to make goggles. |
