SINGLE VISION
Designed to correct farsightedness, nearsightedness, or astigmatism. These eyeglasses have just a single optical prescription correction and distribute focus evenly over the entire lens.
High Index Lenses
High Index Lenses are digitally surfaced designed to be thinner and lighter than regular lenses (1.50 index).
The higher the index,
the lenses are:
QUICK GLOSSARY
Astigmatism
A common and generally treatable imperfection in the curvature of the eye that causes blurred distance and near vision.
Diopter
A unit of measurement of the power of a lens, used for measuring a person’s eyesight.
Myopia (Nearsightedness)
Nearsightedness (myopia) is a common vision condition in which near objects appear clear, but objects farther away look blurry.
Hyperopia (Farsightedness)
Farsightedness (hyperopia) is a common vision condition in which you can see distant objects clearly, but objects nearby may be blurry.
Sphere
Listed as a positive or negative diopter number, the sphere indicates the power of correction needed for nearsightedness or farsightedness.
Plus vs Minus Lenses
The shape of the lenses differ when correcting nearsightedness and farsightedness.
Corrects Myopia (Nearsightedness)
Concave Shape
Symbolized with (-) sign
Corrects Hyperopia (Farsightedness)
Convex Shape
Symbolized with (+) sign
QUICK GLOSSARY
Concave
Having an inward curve like the back of a modern ophthalmic lens.
Convex
Having an outward curve like the front side of a modern ophthalmic lens.
Index
Lens index is a number that describes how thick or thin your lenses are. The higher a lens’ index is, the thinner it becomes. Higher prescriptions require higher index lenses, while lower prescriptions require lower index lenses.
Plus (+) & Minus (-)
A “plus” (+) sign in front of the diopter number means you are farsighted, and a “minus” (-) sign means you are nearsighted.
Plano
Flat, having no power, zero, 0.00. Does not require any plus or minus correction.
Continue learning:
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