Eyewear, explained
The Designer Glasses Editorial Team 
Nose pads are the small contact points — usually two, sometimes built into the frame itself — that carry most of the weight of a pair of glasses and set how they sit on your face. Adjustable ones matter when a standard fit gets the width, height or angle wrong for your particular nose bridge, … Read more
Temple length is the measurement of the arm of the glasses, from the hinge at the front of the frame to the tip that curls behind the ear. It matters because a frame that fits at the temple decides whether glasses sit level, stay put, and look intentional — or slide, pinch, and look slightly … Read more
Glasses that slide down constantly almost always mean the frame doesn’t fit the specific geometry of your face — the bridge is too wide, the temples have too little grip, or the frame is simply too heavy for its contact points. It is a fit problem, not a flaw in you, and it is usually … Read more
Glasses should sit level and stay put without help. The bridge rests on the nose without pinching or leaving red marks, the frame sits low enough that eyelashes don’t brush the lens, and the temples curve gently behind the ears with just enough grip to stay in place through a normal day — no pushing … Read more
No — not reliably. Face-shape rules (“round faces need angular frames”, “square faces need round ones”) are styling conventions built on rough averages, not a science of individual faces. They work often enough to be a decent starting point, and fail often enough that plenty of people look best in exactly the frame the rule … Read more
Lens distortion at the edges happens because a lens is curved and thickest away from its optical centre, and light bends differently the further it travels from that centre. Bigger lenses, stronger prescriptions, and lenses cut off-centre from their blank all make the effect more visible toward the rim. It shows up as a faint … Read more
A lenticular lens is a lens with two zones: a small, optically active circle or oval in the centre that does the actual correcting, and a thinner, much less powerful “carrier” area around it that exists purely to fill the frame and hold everything in place. It’s a design used for very strong prescriptions, where … Read more
Strong prescriptions bend light before it reaches the eye, and that bending changes the size of the image a viewer sees — not the eye itself. Minus lenses, for shortsightedness, shrink the eye behind them. Plus lenses, for longsightedness, magnify it. The stronger the prescription, the more pronounced the effect. What actually causes the minification … Read more
Base curve is the curvature of a lens’s front surface — how steeply it bows outward, measured on a standard scale rather than as a specific power. A flatter base curve sits closer to the face and looks more restrained; a steeper one wraps further around, which is why sports and wrap sunglasses look so … Read more
Pupillary distance, usually shortened to PD, is the measurement in millimetres between the centres of your two pupils. It’s taken so that whoever makes your lenses knows exactly where to position the optical centre of each one — the point where the lens does its clearest, most accurate work sits directly in front of your … Read more
About what you read here. Everything on The Designer Glasses is general information and our own editorial opinion. We research carefully and we say when the evidence is unclear, but we can be wrong, things change, and no article can know your particular situation. Please do your own research and make your own judgement rather than treating anything here as the final word. This is not medical advice, not a diagnosis, and not a substitute for speaking to an optometrist, optician or eye doctor about your own eyes, vision and eyewear. We are writers and researchers, not clinicians. We do not recommend prescription treatments or give doses. If something is painful, getting worse, or worrying you, please talk to a professional — going early is not an overreaction.