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How to Choose Glasses Lenses?

Possibly the most important part of the eyewear buying process is choosing the right glasses lenses. The quality of your lenses, their attributes and their coatings all contribute to how happy you are with your eyeglasses. There are so many options available on the market today, so it can be difficult to decide which type of eyeglass lens is best for you and your unique lifestyle.

This guide to eyeglass lenses will help you better understand what options are available to you and help you choose lenses and coatings to fit your preference and lifestyle.

Lens Types

Learn about the difference between single-vision, near-vision, progressives and bifocals. All prescription lens types can be used for both eyeglasses and sunglasses, unless indicated otherwise on the product.

Distance (Single-Vision)

This lens helps you see things far away. It is usually indicated by a (-) next to the numbers under the Sphere/SPH category of your prescription.

  • Prescription Range:
  • Distance (Single-Vision) Prescription Range

Reading (Near-Vision)

This lens helps you see things up close. The most common use is for reading. It is usually indicated by a (+) next to the numbers under the Sphere/SPH category of your prescription.

  • Prescription Range:
  • Reading (Near-Vision) Prescription Range

Bifocal (Reading & Distance)

This lens has two separate and distinct fields of vision: distance & near. A visible line separates the two.

Progressive (Reading & Distance)

This lens provides seamless progression of many lens powers for all fields of vision. It includes three fields of vision: near, intermediate and distance. There is no line on the lens separating the fields of vision.


A standard lens without any vision correcting powers and adjustments. This is the lens if glasses as a fashion accessory.

Lens Index (Thickness)

The index of your lens, also referred to as the index of refraction or refractive index, is a number that indicates how efficiently the material bends, or refracts, light. The higher the refractive index of the lens, the more slowly light moves through it, and the more the light bends. For you, this means a thinner high-index lens will perform the same as a thick set of standard low-index lenses.

Additionally, higher indexes are able to handle higher prescriptions. If you have a particularly strong prescription, a lens with a higher index may be the best choice for you. Here at KZFOO, we offer lenses with indexes up to 1.74.

1.5 Index - Standard Lens

1.5 Index - Standard Lens

If you are looking for an economical option for your lenses and have a weaker prescription, these lenses may be the right choice for you. These single-vision lenses are the most basic option we offer, and come with all KZFOO frames.

This index is most suitable for prescriptions with an SPH correction of +/-2.25 and below, or a CYL correction of +/-1.50 and below.

1.56 Index - Standard Lens

1.56 Index - Thin and Light Lens

For people with somewhat stronger prescriptions, these lenses may be a better choice than the standard lenses. These lenses are thinner and stronger than their 1.5-index counterparts, handling SPH corrections between +/-5.00 and +/-4.00, and CYL corrections of +/-3.00 and below.

1.59 Index - Polycarbonate Lens

1.59 Index - Polycarbonate Lens

Polycarbonate lenses are the most durable and impact-resistant lenses in our catalog, and come with a 100% UV- protective coating. If you are looking for glasses for children, or tend to spend your time outdoors, we strongly recommend these lenses.

1.6 Index - Thin Lens

1.6 Index - Super-Thin Lens

These stylish, super-thin lenses are an excellent choice for people with strong prescriptions or particularly thin frames. These lenses are suited to people with SPH corrections between +/-4.25 and +/-6.75, and CYL corrections between +/-2.25 and +/-3.00.

1.67 Index - Super-Thin Lens

1.67 Index - Ultra-Thin Lens

These lightweight, thin lenses ensure your eyes do not look distorted from a higher prescription. If you have a particularly strong prescription, this is likely the best choice for you. We typically recommend these lenses for people with SPH corrections between +/-7.00 and +/-9.00, and CYL corrections between +/-3.25 and +/-4.00.

1.74 Index - Ultra-Thin Lens

1.74 Index - As Thin as Possible Lens

Our thinnest lenses are designed for the highest-powered prescriptions. Any thinner and they would disappear! These lenses are best for prescriptions with SPH corrections of +/-9.25 and above, and CYL corrections between +/-4.25 and +/-6.00.

Lens Coatings

Coating can give your lenses different attributes, making them behave differently according to their environment. Some change colors based upon the lighting, while others offer protection from scratches or the sun. To better understand the options available to you; we've listed some of the coatings available in our catalog and what they can do for you.

Anti-Scratch Coating

Anti-Scratch Coating

The Scratch Resistant coating we use , greatly reduces the daily scrapes and scratches that damage your lens over time and affect their clarity. We use a top grade coating that is among the most resistant in the industry. Although the coating is not 100% scratch proof, it makes a big difference.

UV Protective Coating

UV Protective Coating

UV (Ultraviolet) rays from the sun are harmful to the eye and often are associated with cataracts, retinal damage and many other ailments. The UV coating stands strong in fighting those rays from penetrating your eyes while not affecting the overall appearance of the lens.

Anti-Reflective Coating

Anti-Reflective Coating

As its name implies, this coating eliminates reflections of light from the surface of your lens. This allows for people to see your eyes better, and it allows you to see better. You really feel the difference especially when driving at night or long hours in front of a computer.

Lens Tints for Sunglasses

We offer a wide range of sunglasses and specialty tints that will protect your eyes from the sun while having you look as cool as a cat.

Tinted/Polarized Lenses

A way to add an extra dose of color to your look, with a variety of options to choose from as well as selecting the level of tint. Maintains a high level of clarity and visual comfort.

Polarized Lenses

These lenses provide enhanced color contrast provides the highest level of clarity and visual comfort, with reduced reflections and maximum UV protection.

Mirrored Lenses

Mirrored lenses deliver a super cool look with a higher level of clarity, full UV protection, and reduced glare.

To add one of these options to your sunglasses, choose a frame you love, click on choose lenses and in the lens type section select your preferred one.

That's all, please feel free to contact us via if any questions.

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