A.N.S.I.
The American National Standards Institute is a private, non-profit organization that, among other duties, supervises the development of industry standards for consumer goods.

A/R Coating
An anti-reflective coating applied to the rear of a lens to prevent glare from behind, e.g., when flying with the sun at your back and low on the horizon.

Base Curve
The amount a sunglass curves around your face. A regular sunglass is a "6" base, a semi-wrap is an "8" base, and a full wrap-around is a "10" base.

Baseline
An imaginary line drawn across the front of a lens at the point where the temple attaches to the frame. The baseline is the width of the lens in millimeters.

Bayonet Temple
A straight earpiece that does not curve down behind the ear.

Bifocal Drop
The distance, in millimeters, from the baseline on the lens to the top of the reader lens.

Cable Temple
An earpiece made of flexible cable that wraps around the ear and holds eyewear on securely. Our "Gripper" has a cable temple.

Acrylic
An optical quality acrylic plastic, it is the most commonly used lens material in the eyewear industry. Most prescription eyeglasses are made from acrylic.

Diopter Strength
The level of magnification, or "power", in a reading lens, with lower numbers being weaker and higher numbers stronger. We generally carry +1.25 (32), +1.5 (26), +1.75 (22), +2.0 (20), +2.5 (16), +3.0, and +3.5 magnifications (European numbers are in quotations). Stock may vary.

Hard Coat
A scratch-resistant coat that is baked on the lens, it is more durable than a regular air-dried coat.

Hazebuster Lens
A high definition lens that gives the best possible distinction between objects in the distance. It is a "true color" lens (no color distortion).

Nickel Silver
An alloy of nickel and copper that is corrosion resistant, lightweight, and durable, and is the most widely used metal in the eyeglass industry.

Polarized
Lenses which have been polarized will block glare from a horizontal surface. The resulting limited vision will make it difficult or impossible to see your electronic equipment readouts, and will eliminate that glint that you want to see from a cell tower or another aircraft in a see-and-avoid situation. Polarization is not recommended for pilots.

Polycarbon
Invented by General Electric, you know it by the name "Lexan". Highly shatter-resistant, it is the strongest plastic in the world and is used for everything from aircraft canopies to sunglasses. We recommended them for open-cockpit flying, to help protect eyes from bird strikes.

Presbyopia (pres-bee-o-pee-uh)
A universal condition, it is the natural stiffening of the lens in the eye that begins around 38-40 years of age. Correctable with a reading lens, which will focus objects properly on your retina.

Scratch-resistant Coating
An air-dried coating applied to the front of a plastic lens to help prevent scratches. See "Hard Coat".

Temple Length
The distance, in millimeters, from where the temple attaches to the eye frame, to where it begins to curve over the ear.

UVA/UVB
Short-wavelength, high-frequency radiation, ultraviolet (UV) is divided into three bandwidths: UVA (400-320 NM), UVB (320-290 NM), and UVC (290 NM and down). UVA and UVB can cause skin cancer, cataracts, and macular degeneration. Fortunately, UVC, the most harmful, is absorbed by the ozone layer before it reaches the surface of the earth.