Eyewear, explained
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
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.