The only Glasses Glossary you’ll need

If you have been wondering what terms like glazing, pupillary distance, and progressive lenses mean, stroll through this guide for your answers. This glossary includes some of the most common words used in reference to glasses, sunglasses and frames. These words can save you when your eye care professional shoots you with some optical industry jargons.

1. Acetate

Acetate is a plant-based form of plastic extracted from wood pulps and purified cotton linters. Acetate is largely used to make frames and sunglasses as it is more environment friendly, sturdy, lightweight and stylish than plastic. 

2. Anti-glare

Also called anti-reflective, it’s a coating on eye lenses which lets most of the light pass through the lens, rather than being reflected back. This makes your eyes fully visible and saves you from the glare of oncoming traffic while driving. 

PS - All our frames come with anti-glare, anti-UV and scratch resistant coatings at no extra cost!

3. Bi-focal lenses

It is a special lens that helps with both near and far-sightedness. It has two clearly divided sections - the upper portion is used to improve blurry far-sighted vision, while the lower portion is helpful in correcting near vision for purposes like reading.  

4. Blue light

Blue light is a part of the visible light spectrum with the highest energy and shortest wavelength. of seven colours of the rainbow. While it is important for our circadian rhythm, too much exposure to it can harm our eyes. Apart from natural light, we’re exposed to it through digital screens. 

5. Bridge

Also called nose-bridge, it is the part of the frame that sits just above your nose. It is the distance between the inner rims of left and right lenses.

6. Cataract

It is a medical condition - mostly age related - in which the lens of the eye becomes cloudy and opaque, resulting in blurry vision. 

7. Cornea

It is the transparent layer of tissue covering the front and the visible parts of our eye.

8. Glaucoma

Glaucoma is a medical condition resulting due to gradual deterioration or damaging of the optic nerve. The symptoms include eye pain, severe headache and blurry vision. 

9. Glazing

Glazing is the process of crafting out a shape of the lens, according to the frame shape by shaving the edges of the uncut glass until the desired shape is achieved.

10. High index lens

High index lenses have a high refractive index that is able to bend the light passing through it to a greater extent. These are used to make eyeglasses for high prescription numbers. 

11. Hinge

Hinge is that part of an eye frame that connects the front rim of the frame with the arms (called temples). 

12. Hydrophobic

Anything that tends to repel water off its surface is called hydrophobic. In terms of eyewear, a hydrophobic coating is added to lenses to repel water droplets, fog and dust particles from the lens surface.

13. Hypoallergenic

Hypoallergenic is a substance or material that is very unlikely to cause any allergies or reaction. This term is generally used for hypoallergenic acetate material of frames and sunglasses. 

14. Macular Degeneration

It is a medical condition where the central part of the retina (macula) degenerates, resulting in loss of central vision. Blue Light can be a cause behind macular degeneration. 

15. Myopia

Nearsightedness or myopia is a medical defect where the patient experiences blurry far-sighted vision.

16. Ocular height

Ocular height is the distance between the centre of your pupil and the lowermost part of the lower rim.

17. Plano lens

These are zero power lenses, used when one eye suffers an optical defect that needs correction while the other one does not require correction. They are also used in fake glasses accessories. 

18. Polarised lenses

Polarised lenses are able to filter out lights of certain wavelengths and thus block certain light rays from passing through them. 

19. Presbyopia

It is an optical defect where the eye lens is not able to focus on nearby objects. 

20. Pupillary distance

Pupillary distance is the distance between the centers of the left and right pupils of the eye. It is used as a measure for creating the right size of frame for you. 

21. Reading glasses

Reading glasses, or blue light blocking glasses, include a special coating on their surface that aids in reflecting back any blue rays falling on the lens.

22. Retina

Retina is a light-sensitive cell membrane at the back of your eye. Think of it as a projection screen!

23. Transition Lenses

These lenses transition into a darker shade under the influence of high frequency lights like UV rays from the sun. So they act as sunglasses outdoors and glasses indoors, while protecting you against UV rays and blue light. 

24. Ultraviolet light

Ultraviolet radiations are a part of the electromagnetic spectrum of the sunlight. These rays move with a very short wavelength and very high energy, like blue light. 

25. Varifocal lenses

Varifocal glasses, or progressive lenses, come with three different yet seamless partitions where the upper portion is for far-sightedness, middle part for arm-length intermediate vision, and lower part for near vision. They’re more technologically advanced than bi-focal lenses.