Sunglasses Anatomy — The Parts & What Each One Does

Updated: 12 June 2026 · By the Eye-Shop.eu optical team

When you choose sunglasses, it helps to know what each piece is called — from the frame to the nose pad and the hinge. That way you understand the product descriptions, get the right fit and can spot build quality. Here is the full guide with a diagram:

Diagram: the parts of a pair of glasses

The parts of sunglasses — a quick table

Part	What it is	Why it matters
Lens	The "glass" that filters the light	UV400 protection, polarization, colour, clarity
Front (frame)	The front "body" that holds the lenses	Shape, style, material, durability
Bridge	The section that joins the two lenses over the nose	Determines how they "sit" on the nose
Nose pad	The support resting on the nose (or nose pads on metal frames)	Comfort, stability, no slipping
Hinge	The joint connecting temple & front that folds	An indicator of quality & durability (e.g. spring hinge)
Temple	The "arms" that go over the ears	Fit, length, pressure on the temples
Temple tip	The curved end behind the ear	Holds the glasses in place

Lens: the "heart" of sunglasses

The lens is the most important part for eye health. This is where the UV400 protection "lives", along with any polarization (polarized) and the colour/tint that affects vision. See in detail which lens colour to choose. On sunglasses, the numbers on the temple also show the lens size — see what the numbers on glasses mean.

Front (frame): shape, material & style

The front — the frame proper — is the front body that holds the lenses and gives the shape (round, cat-eye, wayfarer, aviator). Materials vary: acetate (rich colour, weight), metal (thin, elegant), titanium (light, hypoallergenic), nylon/O-Matter (flexible, for sport). The frame shape should match your face.

Bridge & nose pad: the right fit on the nose

The bridge joins the two lenses over the nose and determines whether the glasses "sit" high or low. The nose pad is where the frame rests on the nose: on acetate frames it is an integrated saddle, while on metal frames it is replaced by nose pads on adjustable arms. A correct nose pad = glasses that don't slip and leave no marks.

Hinge, temples & temple tips: comfort and durability

The hinge is the joint connecting the temple to the front — a hidden quality indicator: good hinges (often with a spring, flex hinge) survive thousands of open-and-close cycles. The temples pass over the ears and their length (usually 135–150 mm) affects the fit. The temple tip — the curved end behind the ear — holds the glasses in place. Quality in these areas is one of the things you check to tell genuine from fake glasses.

How to read the dimensions

On the inside of the temple you'll see three numbers, e.g. 52‑18 145: lens width – bridge – temple length, in millimetres. These numbers, together with the colour code, help you find the right size. In detail: what the numbers on glasses mean.

The most important part? The lens with UV400

However beautiful the frame is, protection comes from the lens. All sunglasses at Eye-Shop.eu are 100% authentic, from an official distributor, with full UV400 protection — whatever frame shape you prefer.