Glossary of Terms

We have gathered a list of terms from our industry for those of you interested in or researching glasses, blue blockers and sunglasses. Some terms will differ in other countries and by some other organisations, but this is the lingo we use at London Mole.

ACETATE  (AC)
A durable plastic that is used to make our reading glass and blue blocker lenses.

ACRYLIC
A material some glasses frames are made from. Acrylic is machined instead of being moulded. None of our glasses frames are currently made using acrylic. 

ANTI-REFLECTIVE COATING  (AR)
An optical coating typically applied to the lens surface of eyewear, in an effort to reduce reflection

BASE CURVE
Defined in eyewear terminology as being the amount of curve found in any glasses frame. Reading glasses generally have a lower base curve than a pair of wrap-around sports glasses.

BASE TINT
Dyes introduced during lens making processes to establish lens colouring.

BLUE LIGHT
This is the high energy part of the visible light spectrum. Natural blue light comes from the sun, this helps the human body to regulate its sleep and wake cycles. Artificial blue light comes from TV’s, smartphones, computers and laptops as well as LED and fluorescent lighting. Increased exposure to artificial blue light can disrupt the body’s natural sleep and wake cycle making it harder to sleep at night as well as causing eyestrain, fatigue and headaches.

BLUE BLOCKERS
Also referred to as Blue Light Blockers. They filter down blue light and reduce glare, which can reduce eyestrain, headaches and stress levels. London Mole’s Blue Blockers are currently only available with +0.0 Magnification.

CAT (LENS CATEGORY)
The lens category for sunglasses are usually displayed on the inner temple. This category donates the amount of UV and visible light reduction the lenses provide. The Categories go from 0-4 with CAT 0 being low and CAT 4 being for specialist use such as in deserts, while skiing or mountaineering.

CAT 0 - Very limited protection from the sun
CAT 1 - Limited protection from the sun
CAT 2 - Good protection from the sun
CAT 3 - High protection from the sun
CAT 4 - VERY high protection from sun

COATING
Coatings are applied to a lens surface to provide cosmetic and/or utility enhancements. This may include Anti-Reflective, Anti-Glare, Hydrophobic, Scratch Resistant, Polarised.  

CONSTANT DENSITY
This refers to the uniform tinting of lenses, where if a lens is tinted, it is the same tint throughout.

EYESTRAIN
Tiredness or fatigue of the eyes, which can be avoided or drastically minimised with appropriate sight corrective prescription and/or colour or type of sunglasses lenses.

FRAME
The main part of the glasses which holds the lenses, the temples are attached to and the nose pads are incorporated with (Some may also refer to the Frames as being the frame and temples all in one.)

GLARE
Can be caused by direct or reflected light source, causing difficulty seeing.

GRADIENT TINT
Provides a transitioning tint across the lens, typically darker at the top and lighter below. London Mole sunglasses are all a constant density.

HARD COATING
Applied to lenses to increase resistance from scratching and/or breakage.

HINGE
Portion of glasses frame that joins the frame to the temple while allowing the temples to fold inwards for storage.

HYDROPHOBIC LENS
Achieved by applying a special coating to the lens that will repel moisture and prevent spotting of the lens. 

IMPACT RESISTANT
This is the standard of determining the ability of any material to withstand impact without chipping, shattering, fracturing or breaking. Typically, safety glasses are Impact resistant, our aren’t designed for this field so should not be relied upon as safety equipment.

HARD COATING
Applied to lenses to increase resistance from scratching and/or breakage.

LENS
The part of the eyewear you can see through. Our lenses are manufactured from Acetate.

MICROFIBRE
A material commonly used as a cleaning cloth for lenses.

NOSE PAD
The part of the eyewear that rests makes contact with the user's nose. As all of our glasses have been designed in house, they are designed to fit a western nose that is more suited to the market we are in. Other inferior glasses are designed for an eastern nose which is typically flatter and therefore the glasses are not as comfortable to wear for the western market.

PHOTOCHROMIC
This is a property that can be applied to glasses lenses that adjust the darkness of the tint depending on the brightness of the sun/room. This coating is typically only used for prescription eyewear that are worn permanently and not to reading glasses.

POLARIZED LENS
Polarizing is the ability to restrict and reflect specific frequencies of light rays. A polarized lens helps to reduce reflected glare from surfaces, commonly used for driving sunglasses. 

POLYCARBONATE  (PC)
This is a very resilient plastic that is classified as a synthetic resin. It is used to make our frames as it is lightweight, strong and has good scratch resistance.

SCRATCH RESISTANT
This is a term used to identify the ability of a material to withstand scuffs and abrasions. It can either be a coating applied to lenses, or a quality possessed by a base material such as polycarbonate.

SIGHTED, SHORT AND LONG
If a person is short sighted (also near sighted) then they are unable to clearly see things that are far away from them, they can only clearly see things that are close to their eyes. If a person is long sighted, then they are unable to clearly see things that are close to them. Our readers are for long sighted people. They will help to magnify things that are close to their eyes to make them easier to read. We do not currently offer glasses for people who are short sighted.

SPRING HINGE
Also referred to as sprung hinge. This is a high quality hinge that uses a spring for added comfort and durability. The spring allows the temples to flex beyond 90° allowing more comfort for a wearer with a bigger head, and avoids the glasses feeling too tight on the wearers head. The extra flexibility that the sprung hinge offers makes the joint harder wearing. All of our glasses feature sprung hinges.

TEMPLES             
This is the side part of the glasses frame that extends behind the user's ears enabling them to stay in place. The industry terminology is Temple, also may be referred to as arms, side arm, side piece or frame arm.

TRANSPARENT FRAMES
A glasses frame that is clear plastic should be correctly referred to as being transparent.

ULTRAVIOLET RAYS (UV)
Harmful rays from the sun consisting of UVA, UVB & UVC. Whereas UVC is absorbed by the earth’s ozone layer, both UVA & UVB are harmful to the eyes and after prolonged exposure are believed to lead to numerous health conditions.

UV PROTECTION
This is applied as a coating or as a part of the main lens material that blocks harmful UV Rays. The UV rating will be displayed as UV400 which means that it will block UV rays up to 400nm which is 100% of UV Rays. Reading glasses lenses which are not typically designed for UV Protection still provide UV360-UV380 which will block around 80% of harmful UV.

YELLOW LENS
Sunglasses with a yellow lens can dramatically enhance depth perception, and perception in low light conditions. These are frequently used in driving glasses.

 

Diagram of Glasses Parts

Sprung Hinge Detail View

Temple Markings