A frame that curves around the face changes the angle at which the wearer looks through the lenses. Base curve describes lens-surface geometry, while frame wrap describes how the finished eyewear is positioned. They interact, but they are not interchangeable …
Semi-rimless glasses usually hold part of each lens in a conventional rim while a narrow retention cord supports the exposed section. That cord sits in a groove cut into the lens edge. With a thick prescription, the question is not …
A familiar string such as 52–18–140 often means lens width, bridge width, and temple length in millimeters. It is a useful convention, not permission to assign every unlabeled number by position. Product pages, diagrams, temple markings, size menus, and seller …
Virtual try-on is useful for comparing visible appearance: shape, color, brow alignment, and approximate frame width on a face image. It cannot press a bridge against the nose, follow the temples behind the ears, measure a gap beneath a pad, …
A note such as 31/32 suggests two monocular pupillary-distance values, but the slash does not identify which number belongs to the right eye and which belongs to the left. The document’s labels, reading direction, and measurement purpose must establish that …
On an eye-examination record, DVA usually refers to distance visual acuity and NVA to near visual acuity. They describe performance on a chart or near task under recorded conditions. They are not sphere, cylinder, axis, or ADD values, and fractions …
High-index lens material bends light more strongly than a lower-index material, allowing a prescription lens to be made thinner in many frame-and-prescription combinations. The tradeoff is that higher refractive index also tends to increase surface reflection. An appropriate anti-reflective treatment …
Buying two pairs in the same frame model can reduce one variable: the face encounters a familiar bridge, rim, hinge, and temple shape. It does not make the lenses interchangeable. A distance pair, computer pair, reading pair, sun pair, or …
A useful eyewear record is not a photograph of one prescription slip. It connects the clinical prescription used at the time, the frame and lens configuration actually ordered, the measurements collected for that pair, later adjustments, and the wearer’s experience. …
In a rimless frame, the lenses are not passive inserts surrounded by a full rim. Drill holes, bushings, screws, or compression fittings connect bridge and temples directly to the lens. A high prescription can change thickness, weight, surface curvature, and …