In the context of an eye prescription, ‘balance’ refers to the process of ensuring that the corrective lenses for both eyes provide a consistent visual experience. It prevents the brain from perceiving a difference in image size or clarity between the two eyes.
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.
On an eyeglass prescription, ‘PL’ stands for Plano, indicating that no corrective lens power is required for that specific eye. It signifies that the eye’s refractive power is considered normal for that particular parameter.
MOA stands for Minute of Angle, an angular measurement used in rifle scopes to describe adjustment increments and minute aiming points. One MOA equals approximately 1.047 inches at 100 yards, making it essential for precise shot placement at varying distances.
In the context of optometry and ophthalmology, ‘plano’ refers to a lens with no refractive power. When applied to a sphere, it indicates that the lens is flat and does not correct for myopia or hyperopia.
Eye relief is the specific distance between the rear lens of an optical scope and the viewer’s eye where a full image is visible. It is a critical specification for shooter comfort, safety, and visual clarity.
A diopter of 20.0 D denotes an optical power of +20.00 diopters, corresponding to a focal length of 5 cm. It is an unusually high prescription used for severe hyperopia, aphakia, or specialized magnifying lenses.
DS on an eye prescription stands for “distance” and indicates the spherical power required for clear vision at far distances. It is expressed in diopters and appears before any cylinder or add values on the prescription.
20/40 vision indicates that a person must be at 20 feet to see an object clearly that a person with standard ‘normal’ vision can see from 40 feet away. It represents a moderate decrease in visual acuity compared to the 20/20 benchmark.
In an eyeglass prescription, “plano” indicates a lens with zero diopter power. It is commonly used for non‑prescriptive lenses such as reading glasses, safety glasses, or fashion frames, and appears as 0.00 or the word “plano” on the prescription.