Eyeglass Lens Guide: Everything you need to know about prescription glasses lenses

While picking out frame shapes and styles tends to be the exciting part of purchasing new prescription glasses, selecting the proper lens is critical to comfort for all-day wear. We understand that lenses can be a bit tricky to narrow down, so we’ve created this complete guide to help you find the best lens configuration for your next pair of eyeglasses.


Prescription Lens Types

Your lens type refers to which type of vision needs corrected. In today’s market, there are two main types of lenses, single vision and multifocal.

Single Vision: These lenses will correct for nearsightedness or farsightedness, helping you see either up far away or up close, whichever your doctor determines you need.

Multifocal: A multifocal lens will correct for both near and farsightedness all in one lens. A multifocal prescription will have numbers in the ADD column on your prescription. A traditional multifocal lens would be a lined bifocal in which the visible line separates the top portion of the lens used for seeing at distance from the lower portion of the lens which contains magnification for reading up close. 

The modern multifocal is known as a progressive lens, or a lineless bifocal. A progressive lens eliminates the line which signifies an abrubt change and instead gradually progresses from distance to reading magnification. Not only is this gradual progression easier for your eyes to adapt to, it also provides intermediate (computer distance) vision.

The following diagram visually explains the difference between bifocals and progressives:

Prescription Lens Materials

In addition to selecting a vision type, you may also be faced with picking a lens material. Many doctors will recommend a lens material on your prescription, but if they don’t, we are happy to help you make the proper decision for your prescription.

Polycarbonate: Polycarbonate is the industry’s most popular lens material as it is lightweight, impact-resistant, optically clear, and is by nature 100% UVA/UVB blocking. 

Most mild to average prescriptions work best with Polycarbonate which is why approximately 90% of patients select this material.

Trivex: Trivex is similar to polycarbonate in the sense that it is shatterproof, UVA/UVB blocking, and lightweight. Trivex does boast better optical clarity than polycarbonate, which is why it tends to be labeled as more of a premium lens material. It is also slightly more scratch resistant than polycarbonate. 

High Index: High index material is another plastic-based lens material, but due to higher density this material was specifically designed with strong prescriptions in mind. High index lenses are available in 1.67 and 1.74 densities, and to simplify your lens buying process, our expert lab technicians will select the best density to best correct your vision.

If you still can’t decide which lens material is best for you, feel free to reach out and one of our prescription experts would be happy to assist you in picking the perfect material to suit your needs.

Prescription Lens Treatments and Coatings

Anti-Reflective Coating: Also known as A/R coatings, these treatments reduce reflections, thus improving optical clarity and aesthetic appearance. By reducing reflections, especially from overhead light when indoors, others will be able to see your eyes and expressions through your lenses and you will enjoy distraction-free wear.

All of our clear and Transitions lenses feature an anti-reflective coating by default because we find this essential to comfortable wear. We do offer an upgraded premium A/R coating which boasts superb smudge and scratch resistance, and also features a 1-year scratch warranty.

BlueShield Blue Light Coating: The average adult spends up seven to nine hours per day looking at a screen, whether it be a computer, cell phone, or television. What do all of these devices have in common? They all emit damaging blue light which leads to eye fatigue, dry eye syndrome, and even macular degeneration and loss of night vision.

Our BlueShield coating blocks the harmful wavelengths of blue light to protect your eyes and improve optical clarity. Added bonus: our BlueShield coated lenses are clear and do not boast the traditional yellow tint that computer glasses are known for. BlueShield is also scratch and smudge resistant and helps reduce glare, especially when driving at night.

Transitions or Photochromic: Transitions is the brand that popularized photochromic lenses, lenses which lighten and darken according to light conditions. There are three main types of transitions lenses: Adaptive, Xtractive, and Vantage.


Adaptive: This is your standard clear to tinted Transitions lens. These lenses will start as a completely clear lens indoors or at night, and will darken to your choice of grey, brown, or grey-green in direct sunlight. Side note: these lenses will not darken in the car behind a windshield. For this feature, read on!

Xtractive: Xtractive Transitions were created to darken in the car and to transition from light to dark and dark to light faster than standard Adaptive’s. In addition to darkening while driving, these lenses also carry a very slight hint of tint at their clearest, offering an additional barrier of protection for indoor use. This tint is so faint, we find it unnoticeable but worth mentioning. Currently available in clear to grey and clear to brown tints.

Vantage: The Vantage Transitions lens is the world’s first lens which polarizes as it darkens. This means that you can enjoy comfortable unobstructed vision while working at the computer as well as glare-diminishing polarized lenses when outside. The Vantage Transitions are only available in clear to grey at this time.

Polarization reduces glare from the sun as it reflects off of water, snow, ice, or pavement. Polarization also improves optical clarity and color vibrance.

Mirror Finish: While mirror finishes aren’t as popular on prescription eyeglasses, many people enjoy the benefits of a mirrored lens with Transitions. Mirror finishes serve three main functions: aesthetics/looks, repel glare, and boost contrast. On a Transitions lens, the mirror will look like a shiny anti-reflective coating when clear, allowing people to see your eyes through the lens. As the lens darkens, the mirror finish becomes opaque meaning your eyes will be hidden from lookers on.

Whenever a mirror coating is applied to the front of a lens, a backside anti-reflective coating is added to prevent reflected light from becoming trapped behind the lens for distraction-free wear.

If you have any other questions about which lenses and coatings are best for you, we would love to be of further assistance! Please reach us via email or phone with additional questions at info@saltcityoptics.com or 888-507-1230.