About LensOpt

Buying glasses has quietly turned into a maths problem. Your prescription is a grid of numbers, the frame is stamped with three more, ordering online asks for a pupillary distance most people have never measured, and somewhere along the way you’re meant to know whether a 1.67 lens is worth the upcharge or what “category 3” means on a pair of sunglasses. None of it is complicated once it’s explained — but explanations are scattered, and the shops that sell you lenses aren’t always the most neutral place to learn.

LensOpt exists to take that arithmetic off your plate. Rather than one long guide you have to read end to end, the site is built around a set of small, single-purpose calculators, each aimed at one decision in choosing eyewear. The Pupillary Distance Calculator converts between per-eye and both-eyes PD and works out the near value reading glasses use. The Vertex Distance Power Converter shows how a prescription changes between glasses and contacts. The Frame Size & Fit Calculator turns the numbers on a frame into a fit estimate against your PD. The Lens Thickness Estimator shows what power, material index, and frame size do to how thick a lens comes out. The Sunglass Tint & UV Category Finder decodes a lens’s darkness into its filter category and driving rules. And the Contact Lens Cost-per-Wear Calculator turns box prices and a wear schedule into an honest cost per day.

Beyond the calculators, the blog and learn section cover reading a prescription, choosing frames and lenses, contact lenses, sunglasses and UV, and the reasoning behind the numbers the tools produce. The Eyewear & Optics Museum is a browsable collection of frame styles, lenses, the human eye, and the instruments of vision care, with every entry, image, and fact drawn from Wikipedia and Wikimedia Commons.

A few things worth stating plainly. LensOpt is an independent site — not an optician, a lens lab, or a retailer, and not affiliated with any eyewear brand or supplier. It is supported by advertising, which is how the tools stay free with no account required. Every figure the tools produce — a PD, a converted power, a fit verdict, a thickness, a tint category, a cost — is an educational estimate built on the numbers you enter and standard optical formulas, not a prescription, dispensing, or medical advice. For anything that affects your vision or eye health, see a qualified optometrist, ophthalmologist, or dispensing optician. If a tool looks off, or there’s a calculator you wish existed, the contact page is the place to say so.