The Z87 marking on safety glasses indicates compliance with the ANSI Z87.1 standard for eye and face protection. It certifies that the lenses and frames have passed impact resistance, optical clarity, and durability tests required for industrial and laboratory use.
Low bridge glasses refer to eyewear whose bridge—the distance between the two lenses—is shorter than average. This design impacts fit, comfort, and visual alignment, especially for people with a narrower nose bridge.
Single vision glasses have lenses with a uniform optical prescription throughout, designed to correct one type of vision problem such as nearsightedness or farsightedness. They differ from multifocal lenses by providing a single corrective power across the entire lens surface.
A gradient sunglass lens gradually changes from a darker shade at the top to a lighter shade at the bottom. This design reduces glare from the sky while keeping the lower visual field clearer, combining functional benefits with a distinctive style.
In an eyeglass prescription, “plano” indicates a lens with zero diopter power, meaning no vision correction is required. The term is used to denote a non‑prescription, flat lens and appears in the sphere column of a prescription.
Single vision glasses are eyeglasses with lenses that provide a uniform focal point for all distances, commonly used to correct single refractive errors such as myopia (nearsightedness), hyperopia (farsightedness), or presbyopia.
Low bridge fit glasses are designed for individuals whose nose bridge sits lower than the average pupil line. This specialized fit prevents frames from sliding down or resting on the cheeks, ensuring comfort and proper optical alignment. Understanding this distinction is crucial for selecting eyewear that accommodates diverse facial structures.
The designation 10×42 on binoculars means a ten‑times magnification paired with a 42 mm objective lens. This combination influences brightness, field of view, and suitability for activities such as birdwatching, hunting, and astronomy.
Sphere PL is a notation used in eyeglass prescriptions to indicate a plano, or zero‑power, spherical correction. It appears when no spherical adjustment is required for a particular lens, often in reading glasses or low‑vision aids.
Single vision lenses are corrective lenses with a uniform prescription across the entire surface, used for either distance or near vision. They differ from multifocal designs and are the most common type of eyeglass lens.