Sunglasses Glossary
Common Terms & Definitions
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
A
Absorptance:
In regards to a lens this refers to the amount of light absorbed by a specific lens tint or coating. Defined as the specific rate of proportional absorption by any surface to any incident upon the surface (i.e., light waves striking a lens).
Acetate:
Made by chemical synthesis using cellulose and other chemical compounds to produce a durable plastic that can be used to construct frames.
Acuity:
The clarity or sharpness of vision provided by various lens materials and/or coatings.
Acrylic:
Consists of polymers of acrylic acid or acrylates. Sunglass frames can be made from this.
Amber Lens:
Recognized as effectively improving acuity in scattered blue lighting conditions caused by haze, smog or fog. Offering an enhanced clarity in high glare conditions; these are a popular choice for activities such as boating, skiing, and driving. E.g., Brown Lens
Anti-Reflective Coating (AR):
An optical coating typically applied to the lens surface of eyewear, in an effort to reduce reflection.
Arm:
Also referred to as the Temple; this piece attaches to the frame and stretches behind the wearer’s ears, holding sunglasses in place. E.g., Side-Piece, Frame-Arms & Temples.
B
Backside Coating:
Applied to back of polycarbonate lenses to prevent scratching.
Barrel Hinge:
A common hinge connecting the temple and the frame of sunglasses.
Base Curve:
Defined in sunglass terminology as being the amount of curve found in any sunglass frame. A California Classics style has a low base curve; while sports styles typically have a high base curve and are commonly referred to as wrap-around sunglasses.
Base Tint:
Dyes introduced during lens making process to establish lens coloring.
Bridge:
Space between sunglass lenses, extending across/over the wearer’s nose. Designed to support a majority of frame weight.
Brown Lens:
Also referred to as an Amber Lens, this lens color is believed to enhance clarity, lessen glare and best for outdoor activities.
C
Carbon Fiber:
A common term used to identify carbon fiber reinforced polymer, known for its strength-to-weight ratio. i.e., highly durable & lightweight.
Clear Lens:
Referring to a lens that has no coloring or tinting. Can (and should) provide 100% UV Protection.
Coating:
Applied to lens surface to provide cosmetic and/or utility enhancements.
Color-Mirrored:
Coating applied to outside lens that appears mirrored with various color tints, such as blue, gold, red, green or purple. E.g., Revo coating, Flash Mirror Coating.
Colored Transparent Frame:
A type of frame color that is semi-transparent with a color tint.
Constant Density:
Refers to the uniform tinting of lenses, an alternative to Gradient tinting.
Contrast:
The varying degrees of tones and values in eyesight. Lens colors will directly affect the wearer’s perception of contrast; which can improve or diminish vision acuity dependent upon lighting conditions.
CR-39:
Lightweight plastic made of hard resin, commonly used for lenses. Highly resistant to scratching and/or shattering, not be confused with Polycarbonate. This material is also easily tinted to virtually any color.
D
Display Rack:
Used to display assorted selections of sunglasses. Available in numerous styles and materials.
Double Gradient:
Refers to a lens, which possesses a tint across both top & bottom while having a light tint through the middle.
E
Earpiece:
Typically a plastic or rubber coating or sleeve that resides along the length of the temple resting on the wearer’s ear. Most commonly seen on sunglasses with a metal or wire frame or temple. E.g., Temple-Tip.
Endpiece:
Residing on the outer sides of the frame surrounding the lenses, this portion of the frame is used to attach the temples to the front part of the sunglass frame.
Eyestrain:
Tiredness or fatigue of the eyes, which can be avoided or drastically minimized with appropriate colored lenses.
F
Flash Mirror Coating:
Another term for a standard mirror lens coating applied to lenses, typically in silver, blue or gold.
Frame Arm:
Extends behind the ear, holding sunglasses in place while being worn. E.g., Arms, Side Piece & Temple.
Frame:
Portion of sunglasses that lenses rest within, which temples are attached to via end pieces and/or hinges.
Frame Rims:
Part of the sunglass frame in which lenses are inserted.
Full Rim:
Referring to a sunglass style that possesses an entirely enclosed lens.
G
Glare:
Can be caused by a direct or reflected light source, causing difficulty seeing. See also Reflected Glare*
Gradient Tint:
Provides a transitioning lens tint quality, typically darker above, and lighter below.
Gray Lens:
A neutral tone believed to provide the truest colors and is an all-purpose tint. Believed to provide the highest level of glare resistance, while not enhancing contrast.
Green Lens:
Known to provide increased contrast in low light situations, while minimizing eyestrain in bright light. Minimal blue light is filtered by green lenses.
H
Half-Rimless Sunglasses:
Referring to eyewear that possesses only the upper portion of a frame rim. Typically found with wire frame eyewear. E.g., Semi-rim & Rimless.
Hard Cases:
Refers to a style of sunglasses case which has a hard outer shell, frequently 'snap' close upon placing pressure on the lid.
Hard Coating:
Applied to lenses to increase resistance from scratching and/or breakage.
Hinge:
Portion of sunglass frame that joins the frame rim and end piece to the temple, while allowing the temples to fold inward.
Hydophobic Lens:
Achieved by applying a special coating to the lens that will repel moisture and prevent spotting of the lens.
I
Impact-Resistant:
Standard of determining the ability of any material to withstand impact without chipping, shattering, fracturing or breaking.
Interlocking Hinges:
Built into the temple of the sunglasses, operates similarly to a barrel hinge. Will appear like a small pin screwed into the frame.
Iridium:
Common component when making mirror coatings.
L
Lens:
Part of eyewear that you see through. Can be manufacturer from numerous materials such as CR-39, or Polycarbonate.
Lens Tint:
Refers to the density and shading of lens, e.g., Smoke Tint, Gradient Tint.
M
Metal Frame:
Refers to a frame made of metal or wire, common among many aviator styles of sunglasses.
Microfiber:
A material commonly used as a cleaning cloth for lenses as well as storage bags with draw-string closures for sunglasses.
Mirror Coating:
A common coating applied to the lens, noted for its reflective qualities. Contains iridium and can be colorized.
N
Nose Pad:
Present on many styles of sunglasses, refers to an oval plastic piece attached to Pad Arm designed to enhance comfort and support weight of frame.
P
Pad Arms:
Piece of material extending from the frame rim, used to attach the nose pad, capable of providing a customized fit for the wearer.
Photochromic:
The ability to undergo a reversible change in color (or shade) when exposed to specific frequencies or intensity of light, allowing the effect to only occur in sunlight rather than artificial light. Often applied to lenses, however after long-term exposure to intense sunlight the darkening effect will become irreversible.
Polarize:
The ability to restrict and reflect specific frequencies of light rays.
Polarized Lens:
Can be infused during the lens making process or applied as a coating to the lens. The final effect eliminates reflected glare of surfaces. Commonly preferred during outdoor activities.
Polycarbonate (PC):
A notoriously resilient plastic created by various carbonate groups. Classified as a synthetic resin. Commonly used to manufacture lenses due to its scratch resistant, lightweight qualities.
R
Reflected Glare:
Caused by reflected light sources, generally generating a much stronger, and more damaging glare than the originating source. (i.e., sunlight reflected off of water will cause more damage to the eyes than the original light waves.)
Revo Lens:
Refers to a mirrored coating that reflects a coloring. I.e., red revo, blue revo, gold revo.
Rimless:
Referring to sunglasses that have only a partial frame rim into which lenses are inserted.
Rose Lens:
Similar to brown and amber lenses, in that it effectively scatters blue light and enhances contrast.
S
Scratch-Resistant:
This is a term used to identify the ability of a material to withstand scuffs and abrasions. Can be a Coating applied to lenses, or a quality possessed by materials used as lenses, i.e., PC & CR-39.
Semi-Rim
Synonymous with half-rim and rimless; referring to a frame style that forms only the upper portion of the frame rim, common with wire frame styles.
Side Pieces:
Another term for the Temple of sunglasses, which extend over and behind the wearer’s ears, e.g., Arms, Frame Arms.
Smoke Tint:
Common reference to the shading applied to the lens to darken/absorb light rays.
Soft Cases:
Refers to sunglass cases made of flexible materials. Available in numerous types of materials, patterns and sizes.
Spring Hinge:
A high quality hinge alternative that provides added comfort and durability. Functions in a manner allowing the joint more flexibility.
Sweat Bar:
Common frame piece in metal sunglasses, used to connect the lenses. E.g., Top Bar.
Sunglass Straps:
An accessory for sunglasses that attaches to the temple-tips, used to allow sunglasses to rest around the wearer's neck. Can be found in useful floating materials, which will prevent losing sunglasses in bodies of water.
T
Temples:
Piece of sunglasses extending behind the ears, enabling them to stay in place. E.g., Arms, Side Piece & Frame Arm.
Temple Tips:
Made of soft rubber or plastic and applied to the tip of the temple for added comfort, also assists in keeping sunglasses in place while worn. E.g., End Pieces.
Top Bar:
Portion of frame that joins lenses.
Transparent Frames:
A sunglass frame that is clear plastic, often used in combination with a color cast. Also called Translucent Frames.
U
Ultraviolet Rays (UV):
Harmful rays of the sun, consisting of UVA, UVB & UVC. Whereas UVC is absorbed by the earth’s ozone layer, both UVA & UVB are harmful to the eyes and after prolonged exposure are believed to lead to numerous health conditions.
UV Protection:
Can be applied as a lens coating, or embedded into the lens; successfully blocking all UV rays.
V
Visor Clips
A sunglass accessory used to attach sunglasses to vehicle visors for easy storage and reach.
Y
Yellow Lens:
Dramatically enhances depth perception, and perception in low light conditions. Frequently used for driving glasses.