If terms like ‘high-index’, ‘progressive’ and ‘multi-coat’ always puzzled you, you’re not alone! We’re here to breakdown the eyewear jargon and help you understand the basics of choosing a pair of prescription lenses.

Credit: Oliver Peoples


Plastic lenses are the norm nowadays as they are much lighter (than glass), less brittle and allow for the layering of special coatings (see Coating).


The index of your lenses refer to the thickness of it. Typically, the index is chosen based on your degree or type of frame you choose. As metal frames are slimmer than plastic frames, thicker lenses tend to look more obvious. So in this case, we would recommend opting for higher index lenses.


There are two main types of lenses: single vision or multifocal.

Single vision lenses correct one type of vision problem e.g. looking near or looking far.

Within the category of multifocals, there are bifocal, trifocal and progressive lenses. These lenses provide correct multiple fields of vision best explained in this graphic:

Credit: Pinterest

Single vision lenses are then enhanced by coatings based on the wearer’s lifestyle and needs (see below). Multifocal lenses, especially progressive lenses, similarly come in many variations with new features constantly being developed and released every year. Examples of improved features include wider field of vision, gentler graduations and most recently, lenses that minimise head movements typically required to find focus.


R&D in recent years has also given rise to a variety of lens enhancements. Some features are exclusive to certain brands while others are offered by multiple brands. The quality/durability of each feature varies according to the manufacturer and here at Kwong Shin, we usually make recommendations based on the feedback we receive from customers who have tried out the lenses themselves.

Starting with the terms that are more easily understood, these coatings are commonly found:

  • Anti-reflective
    a.k.a. multi-coated lenses that reduce reflection on the surface and increase light transmission
  • Scratch resistant
  • Water repellant
  • Smudge resistant
  • UV blocking
  • Dirt repellant
  • Impact resistant
  • Anti-fog
    a.k.a. lenses that are less likely to fog up when moving from a cooler to warmer environment

The following coatings are a little more complex and we have further elaborated:

  • Blue light filter
    a.k.a. lenses that neutralise blue light and reduce digital eye strain
  • Photochromic treatment
    a.k.a. lenses that change colour when exposed to sunlight to reduce glare and protect against UV rays
    Available variations:
    > Extra dark lenses that also change colour when the user is seated in the car, and remains slightly tinted indoors (grey)
    > Standard colours (grey, brown, green)
    > Special colours (amethyst, amber, emerald or sapphire)
  • Digital lens by ZEISS
    a.k.a. lenses designed for people in their 30s and 40s who are experiencing the first signs of presbyopia and require a pair of lenses that will ease them into progressive lenses
  • Office lens
    a.k.a. lenses specifically for near and mid distance reading and computer work
  • Myopia-stabilising
    a.k.a. lenses designed to slow down the rate of myopia progression among children
  • Post contact lens usage (EnergizeMe) by ZEISS
    a.k.a. lenses meant to help contact lens wearers relax tired eyes after a long day and prevent eye strain caused by digital devices
  • Driving lenses
    a.k.a. lenses designed to help drivers cope with difficult light conditions and provide a field of vision best suited for driving


And that’s it! We hope this helps you in making a more informed decision the next time you make a pair of glasses 🙂