Eyewear, explained
The Designer Glasses Editorial Team 
A gradient lens is tinted darkest at the top and fades to little or no colour towards the bottom. It exists mainly to cut glare from overhead sun and reflective surfaces while keeping the lower field of vision clearer — useful for driving, reading a phone, or checking a menu without lifting the glasses. The … Read more
A mirrored lens has a wafer-thin metallic coating applied to its front surface, so a portion of visible light bounces straight back off the lens instead of passing through. It cuts the glare that reaches the eye and gives the lens a reflective, often coloured, surface — but the coating itself does not determine how … Read more
Sunglass lens category numbers, from 0 to 4, describe how dark a tint is — nothing more. Category 0 is barely tinted, category 4 is very dark and unsuitable for driving. The number has no bearing on UV protection, which is a separate rating entirely, usually shown as UV400. What do the category numbers actually … Read more
Polarised lenses are a bad idea whenever the situation depends on you reading a screen, an instrument panel, or an icy patch through glare. Polarisation works by blocking the horizontal glare that bounces off flat surfaces — water, tarmac, snow — but that same trick can hide useful information or wash out digital displays, which … Read more
Polarised lenses contain a chemical filter, embedded in or laminated onto the lens, that blocks horizontally oriented light waves — the kind that bounce off flat, reflective surfaces like water, wet tarmac, glass and car bonnets. That reflected glare normally arrives as an intense, uniform band; the filter absorbs most of it, so what reaches … Read more
UV protection blocks ultraviolet radiation from reaching the eye and is a health measure. Polarisation filters out horizontal glare — the harsh reflected light bouncing off water, glass, wet tarmac or a car bonnet — and is a comfort and clarity measure. A lens can have either, both, or neither, and a dark tint on … Read more
A dark lens without a UV filter tricks the eye into staying more open than it would in daylight, because the tint tells the pupil it’s dim. Without UV blocking, that wider pupil lets in more ultraviolet light than if no sunglasses were worn at all. The darkness is the problem, not the protection. How … Read more
UV400 means the lens blocks light up to the 400 nanometre wavelength — which covers the entire UVA and UVB spectrum reaching the earth’s surface. It’s a filter rating, not a tint level. A lens can be pale grey and rated UV400, or black as tar and offer none at all. The number tells you … Read more
A frame looks expensive when its proportions are considered, its material is dense and evenly finished, and its details — hinges, bridge, temple tips — are built rather than glued on as an afterthought. Price and appearance often correlate, but not reliably. Plenty of cheap frames borrow the visual cues of expensive ones, and plenty … Read more
A bold frame stops working the moment it stops being the thing you notice second. If the frame is the first and only thing anyone registers — before the face, before the outfit, before the context of the room — it has tipped from statement into distraction. That tipping point is about proportion, colour and … 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.