Eyewear Glossary | Eyewear Dictionary | LensCrafters

OUR EYEWEAR GUIDE
FROM A TO Z

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Curious about the ins and outs of eyewear? Read through our guide to learn more about your eyeglasses and sunglasses.

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ACETATE

A modern alternative to petroleum-based plastic made from plant-based cellulose and all-natural cotton flakes. Eco-sustainable, skin-friendly and completely hypo-allergenic, acetate takes color beautifully and can be blended to mimic the extraordinary patterns of nature.

ASIAN FIT

Designed to fit faces with higher cheekbones, it has less curvature and minimal bridge.

BRIDGE

Joins the eyewires to distribute weight evenly across nose.

BRUSHED

A finish used to give metal frames a softly textured rather than polished look.

BROW BAR

An upper bar along top of frame which has become a trend-signal.

CARBON FIBRE

A frame material with a high strength to weight ratio that makes it extremely durable and highly rigid.

COATING

A treatment applied to the surface of your lens to add functional protection.


  • Anti-reflective coating (AR) eliminates reflections from front and back of lens to block glare.
  • Hydrophobic coating repels water, sweat and reduces spotting on lens surface.
  • Scratch-resistant coating protects lenses from abrasions and scratches with a resin film

CORE WIRE

The wire frame inside of acetate temples. Some styles show off this underpinning in a clear acetate.

DOUBLE BRIDGE

A two-piece bridge design that adds stability and classic design.

END PIECE

Links the eyeglass front to the temple and can feature embellishments.

EYE WIRE

The piece that holds the lens in place. It varies dramatically from one from to another.

FRAME ID

A standard reference printed inside the temple. It includes brand, model, color, size, and temple length.

FRONT PIECE

The front part of the eyeglass frame.

HD LENSES

HD lenses are made using digital computer technology based on a digital scan of your eyes. The lenses are customized precisely for your specific vision correction and one-of-a-kind eyes.

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HINGE

The open &close part of the frame that connects the rim to the temples. Click here to see the hinge on Anatomy of a Frame.


  • Flex hinges use an internal spring to give you extra durability with greater flexibility.
  • Light ray hinges are made of ultra-flexible and resilient titanium.
  • Mono-block hinges are made from a single block of metal so there’s less chance of breakage.
  • Pinless front hinges made of nickel-silver are used in acetate or nylon frames.
  • Rivet hinges are fixed to the front or temples using rivets inserted into the hinges ’twin holes to create a vintage look.

Lens power

Refers to the strength of the lens correction and is commonly used to describe the different correction areas (near, mid, distant vision) in multi-focal or progressive lenses.

LENS MATERIALS

  • Glass used to be the material of choice but has been replaced by lightweight, durable high-tech plastics that offer optimum clarity.
  • Polycarbonate is a type of high-index plastic that's thinner, lighter and impact resistant.
  • HD is a digital lens that provides the highest level of detail and clarity especially in high index prescriptions.

MATTE

Describes a non-shiny surface that is used in both metal and acetate frames to give a non-reflective, flat finish.

MEMORY METAL

A metal alloy used for frames that's usually made from titanium and nickel. It keeps its shape while offering a fit that's lightweight, strong and comfortable.

MONEL

Is a nickel and copper alloy used in metal frames. It’s lightweight and highly resistant to corrosion.

NICKEL SILVER

An alloy of nickel and zinc. It’s more rigid than other mixed metals and is often used in eyewear for hinges, ear pieces, and bridges.

NYLON FIBER

A lightweight and resilient alternative to acetate frames that comes in a wide array of colors and styles.

NOSE PADS

The soft plastic cushions that sit on either side of the nose.

OVERSIZED

Eyewear that describes a larger than usual frame silhouette typically for square, round, or rectangular shapes that gives you a dramatic, sophisticated look.

PAD ARMS

They hold the nose pads in place to keep your eyeglasses comfortably balanced across your nose.

POLYCARBONATE LENS

Thinner and lighter than other plastic lenses and more durable making them a go-to lens choice for kids and active adults. Also great for strong prescriptions because it corrects without adding thickness.

PROTECTION INDEX

Refers to the level of UV eye protection in sunglasses. Always choose lenses that are rated UV400 or higher which means they'll block 99.9% of UV rays.

POLARIZED LENS

Sunglasses treated with a coating that filters out horizontally reflected glare to give you sharper details, enhanced colors, and enhanced depth perception.

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PROGRESSIVE LENSES

offer up to three vision powers in one lens making them a great option for older adults with a need for near, mid and distance vision correction.

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RETRO

A vintage look characterized by rounded shapes, rivets, and etched metal or coin edge tooling.

SINGLE VISION

One correction throughout entire lens (usually for distance or reading).

STAINLESS STEEL

An affordable alternative to titanium. It offers a lightweight feel and hypoallergenic benefits because it’s nickel-free.

TEMPLE

Also known as a ‘stem’ and is the side bar piece on eyeglasses or sunglasses that extends from the hinge to the ear piece. Temples can be decorative or purely functional and come in a variety of styles.

TITANIUM

A premium metal that’s lightweight, hypo-allergenic, and highly resistant to corrosion. It’s super strong and surprisingly light.

TEMPLE TIPS

The curved pieces that hold on around your ears. On metal frames, they can be in a contrasting acetate or other material to add fashion to function.

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