Glasses for a diamond face: oval, cat-eye and browline frames, and why

The short answer

For a diamond face, choose oval, cat-eye (upswept) or browline frames. A diamond face is widest across the cheekbones and narrows at both the forehead and the jaw; these three frame shapes add width or detail at the brow, where the face pulls in, and keep the overall line soft. Avoid narrow, angular frames, which echo the sharp points of the cheekbones.

This follows the optician's rule of contrasting and balancing the face. It is a trade convention, not a result from a controlled study, but it rests on a simple idea: the frame sits right at the level where a diamond face changes width, so it can either fill out the narrow brow or sharpen the corners at the cheekbones.

How to tell if your face is diamond-shaped

Diamond is one of the less common labels and easy to misjudge. Use a photo from about 1.5–2 metres, straight on, at eye level, with your hair pulled back off the forehead and temples and glasses off.

A close selfie is especially misleading for this shape. At arm's length the camera enlarges the centre of the face; a 2018 paper in JAMA Facial Plastic Surgery modelled the effect and estimated about 30% extra apparent nose width at around 30 cm. The same middle-of-the-face swelling makes the cheekbones look wider than they are, so a close selfie can make almost anyone look diamond-shaped.

From a distance photo, check three things:

1. Cheekbones against forehead. The width across the cheekbones is clearly greater than the width of the forehead at the temples, often with a visible inward curve at the temples.
2. Cheekbones against jaw. The jaw, just below the ears, is also clearly narrower than the cheekbones.
3. The chin. The jaw narrows to a fairly small, often pointed chin.

If the forehead is as wide as the cheekbones and only the jaw narrows, you are closer to heart-shaped. If the cheekbones are only slightly wider than forehead and jaw, you are closer to oval, where most frames work. If width and length are close and the outline is curved, read glasses for a round face instead.

What suits a diamond face, and why

Oval frames

Soft, curved, slightly wider than deep. An oval frame adds horizontal width at eye level and softens the angular outline without adding any points of its own. It is the easiest everyday choice for this shape.

Cat-eye or upswept frames

A frame whose outer top corners lift slightly. The lift adds width right at the brow and temples, where a diamond face is narrow, and draws the eye up and out from the cheekbones. For men this is usually a subtle upsweep rather than a dramatic cat-eye; many browlines and retro acetate frames have it.

Browline frames

A strong top bar (often acetate) over a lighter lower rim. The heavy top line adds width at the forehead, and the light lower half keeps attention away from the cheekbones. On a diamond face this is the most direct way to balance the narrow brow.

What to avoid, and why

Narrow, angular frames. Small, sharp rectangles or geometric frames repeat the points of the cheekbones and the chin. Because they are narrow, they also leave the forehead and temples bare, so the face looks narrower at the top and the cheekbones look wider by comparison.

Related choices that push the same way:

• Frames wider than the cheekbones, which overhang at the widest part of the face and exaggerate it.
• Bottom-heavy frames, which add weight near the cheekbones and the narrow jaw rather than at the brow.
• Very shallow frames that sit on the cheekbones, which draw a line exactly across the widest point.

These are not banned; they just work with the angles rather than against them.

Getting the size right

• Width. About as wide as the cheekbones, not wider. The frame should sit inside the widest part of the face.
• Depth. Medium. Very deep frames can rest on the cheekbones, which pushes them up and draws attention there.
• Bridge. The frame should sit without sliding or pinching. If the frame touches your cheeks when you smile, the bridge is too low or the frame too deep.
• Height. The top rim near the eyebrow line, so the brow line of the frame and your own brows work together.

Sizes are usually printed inside an arm, as something like 52□18 145: lens width and bridge in millimetres (on the boxed measuring system defined in ISO 8624), then arm length.

What to say to the optician

"My cheekbones are the widest part of my face and my forehead's narrower, so I'm looking for an oval, a browline or something slightly upswept. Nothing narrow and angular, and not wider than my cheekbones. Can you check the frame doesn't sit on my cheeks?"

Ask to try a browline and an oval side by side. If your prescription is strong, mention it, since it affects how thick the lens edges look in larger frames.

Not sure of your shape? Find it from one photo.

Colour

Colour along the top of the frame strengthens the effect you want, so a two-tone browline or a frame darker at the top works well. Pick the colour family by undertone: warm skin suits tortoiseshell, brown and gold; cool skin suits black, silver, navy and grey.

Sunglasses

Sunglasses that suit you follow the same frame shapes. Oval, browline and gently upswept sunglasses all work; narrow, sharp-edged sport shapes are the ones to try with caution.

Trying them on properly

Photograph each pair from about a metre away, straight on and at a slight angle, with soft light from the front. Hard light from the side or above deepens the hollows under the cheekbones and makes every frame look sharper on a diamond face.