In an eyeglass prescription, ‘Add’ refers to the additional magnifying power required for near-vision correction. It is typically prescribed for individuals with presbyopia to assist with reading and close-up tasks.
The term ‘Add 2.25’ on an eye prescription refers to the additional lens power needed for near vision, commonly used in multifocal or bifocal lenses. It indicates a +2.25 diopter addition to the distance prescription to aid with presbyopia, a condition affecting close-up focusing.
A soft camera lens produces images that lack sharpness, contrast, or fine detail resolution. This characteristic can result from optical design, manufacturing variances, or specific shooting conditions. Understanding lens softness is essential for photographers evaluating equipment performance.
15/20 vision is a measure of visual acuity that indicates the clarity or sharpness of vision relative to standard eyesight. It means that what a person with normal vision can see clearly at 20 feet, a person with 15/20 vision can see clearly at 15 feet.
In the context of contact lenses and optometry, ‘plano’ refers to a lens with no corrective power. A plano lens does not magnify or diminish an image, meaning it is functionally neutral in terms of vision correction.
The notation +4.5 is primarily used in sports betting to indicate a point spread advantage for an underdog. It is also utilized in optometry to denote lens prescription strength for hyperopia.
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.
Pd 60/57 is a notation commonly used in eyeglass prescriptions to indicate the pupillary distance (PD) for distance vision (60 mm) and near vision (57 mm). This measurement ensures that lenses are aligned correctly with the wearer’s pupils for optimal visual clarity.
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.
Plano on an eye prescription indicates a lens power of zero diopters, meaning no corrective power is required for that eye. It is commonly used for patients with normal vision or for the non‑dominant eye in certain contact lens prescriptions.