Eyewear A-Z - All things eyewear and more! - Oscar Wylee
Eyewear A-Z - All things eyewear and more! - Oscar Wylee

Glossary Of Eyewear Terms

Acetate frames

Frames made from the popular material acetate - a nylon-based plastic made from renewable and organic material. Acetate frames can come in many colours and are great for glasses frames as they are strong, flexible and are hypoallergenic, perfect for those with sensitive skin. Compared to regular plastic frames that could cause irritation, come in limited colours and are usually non-adjustable. Check out our acetate collection here.

Add power

A magnifying power for close up activities such as reading, and used in multifocal and bifocal lenses.

Anti-reflective coating (anti-glare)

A coating added to the lens that makes it anti-reflective, scratch-resistant and added UV protection.
Oscar Wylee also offers a Premium Anti-Reflective lens coating with added advantages of extra scratch resistance, smudge resistance and anti-static.


Also known as the temple of a pair of glasses, they are the long arms on the side of your glasses frame that sit over your ears to help your eyeglasses sit securely.


A machine that helps give your Optometrist an idea of your prescription by testing your eye's ability to focus. This also checks the pressure of the eye to help check for any signs of Glaucoma. The Optometrist will then use these results to fine-tune your prescription.


Specifies the angle between 0-180 degrees that your SPH (sphere) and CYL (cylinder) overlap to give the clearest vision and correcting astigmatism.

Blue Light Filter/Lenses

A lens add-on that can help block blue light emitted from digital screens and may help you sleep better.
To find out more, check out our Blue Light Glasses page.

Cat-eye frames

A playful eyewear shape universally known for and recognised by its upswept corners at the top outer edges joining the temples to the frame. Check out our cat eye frames here.

Colour blindness

A condition affecting the perception of colours. Also known as Colour Vision Deficiency.

Contact lenses

Contacts or contact lenses are thin disc-like lenses that sit directly on the surface of the eye. It should be noted that because they sit on the eye, compared to eyeglasses that sit about 12mm away from the eye, your eyeglass prescription and contact lens prescription are not the same.


This is the amount of lens power for astigmatism. If nothing appears in this column, you have little or no astigmatism that requires any correction.


Pupil dilation allows the optometrist to see inside your eye. Using special eye drops, the pupil is forced to stay widened for the optometrist to check the health of the retina and optic nerve located at the back of the eye.


A lens diameter is the width of the lens on a pair of frames.

Driving vision test

A vision test for assessing your fitness to drive. When applying for or renewing your licence, you may be required to pass this eyesight test.

Expiry Date

The date at which your glasses prescription expires. As the condition of your eyes can change it's always good to keep up-to-date with all eye health checks. Dispensers are unable to use an expired prescription to produce new glasses.

Eye drops

Lubricating eye drops are used to help refresh and moisten eyes if you have dry eyes and can provide temporary relief for irritated eyes.


The material part or the rim of a glasses frame that holds the prescribed lenses in place.

Frame size

Those numbers you see on the inside of glasses arms tell you the size of them. For example 51-18-145. In order, it will tell you the width of the lenses on the frame, the bridge size or distance between the lenses and the arm length.

Half-rim glasses

A style of glasses in which the lenses will be covered by the top rim of the glasses.

Hard coat

A scratch resistant coating providing durability and longer lasting lenses.

Health fund extras

If you have optical extras as part of your health fund this means you will be able to claim the cost of your prescription glasses through your health insurer for low or no out-of-pocket expense. Learn more here .

High-index lenses

A lens option perfect for those with a stronger prescription as high-index lenses are thin and lightweight, ensuring an even more comfortable fit.

Ishihara test

A colour perception test that is used when screening for signs of colour vision deficiency.

Low Bridge Fit

Made with those who have a low nose bridge, low bridge fit frames are made with higher nose pads to help keep glasses from sliding down.

Mirror tint

A reflective coating added to the outside of the lens that can provide reduced glare, effective for when in an environment that will bounce light into the eye from surfaces such as snow or on a very sunny day.

Nose bridge

The little ‘bridge’ that connects the front of the glasses frame together.

Nose pads

The small clear pads you find on some glasses that sit on the sides of the nose for additional support or a better grip.


Derived from Latin, Oculus Dexter meaning Right eye.


Derived from Latin, Oculus Sinister meaning Left eye.


Clear lenses that tint to grey when exposed to UV light.


Lenses with no prescription.

Polarised lenses

Lenses with a coating applied to the lens to darken it and add colour, also cutting out glare on the horizontal wavelength. Includes our Basic Anti-Reflective coating as standard.


The results of your eye test recorded by an optometrist or ophthalmologist specifying what they have considered necessary to create your corrective lenses.


In a prescription, prism is sometimes needed to improve double vision or assist with focusing, or to compensate for eye alignment problems and can be denoted with directions such as base up, down, in, and out.


Also known as progressives, multifocal lenses allow for multiple focal lengths in the lens making it easier to see at a variety of distances without the need to constantly switch between your reading and distance glasses.

Pupillary distance

The measurement in millimetres of the distance between each pupil. Required when ordering a new pair of glasses, it is used to ensure that your lenses are positioned properly to give you clear vision. Learn how to measure your own PD here.

Reading glasses

Glasses used for close up activities that come with a preset magnification strength.


A refraction test, also known as a vision test, is part of an eye exam. You will be asked to read some small text through a series of lenses to see which lens is better, determining your prescription.


A thin layer of cells lining the back of the eye. The retina transmits visual information to your brain through the optic nerve allowing you to see.

Rimless glasses

A frameless style of eye wear in which the lens is directly attached to the temples and nose bridge. An elegant and minimalist choice of eyewear to suit anyone.

Segment height

Necessary for multifocals, seg height is the measurement in millimetres from the bottom of your glasses lens to your pupil.

Single-vision lenses (SVD)

Single vision lenses are used for far sighted distances like driving, tv, or walking around. Some people can have a SVD prescription and use this for everything. This is called a constant or SVC (Single Vision Constant) prescription.

Snellen Chart

A chart that consists of different sized letters that you will be asked to read as part of your eye test and will help the Optometrist determine your prescription.


This is the amount of lens power, measured in diopters, prescribed to correct nearsightedness or farsightedness.

SVI lenses (Single Vision Intermediate)

SVI lenses give clarity around 1m away. Good for computer use or reading sheet music when playing an instrument.

SVN lenses (Single Vision Near)

SVN lenses are used for close vision activities like reading books or magazines.


Also known as the arm of a pair of glasses, they are the long stems on the side of your glasses frame.

Tinted lenses

Lenses with a dye added to them to make them darker for sunglasses. Includes our Basic Anti-Reflective coating as standard.


A strong, lightweight and corrosion-resistant metal used for eyeglass frames.


An amorphous thermoplastic polyetherimide (PEI) material. Ultem is ultra light, durable and super flexible on the temples of the glasses frame.

UV Protection

Ultraviolet protection lenses can help protect your eyes from the potentially harmful sun rays. Not to be confused with polarised lenses which only help to cut out the glare from the sun, unless otherwise labeled.

Visual Acuity

Part of a comprehensive eye test, a visual acuity test will check your ability to recognize shapes and details of objects from a certain distance.

Visual field machine

A machine that helps with checking for signs of Glaucoma, a possible stroke or a brain tumour. It checks the central and peripheral vision to find any abnormalities.

Due for an eye test? Book now:

We recommend that everyone should have an eye test with an optometrist at least once every 2 years.

*Free eye test with optical glasses purchase on the same day. Otherwise $30.