Though you as a consumer get to decide a lot about how your glasses look, you don’t get to decide what type of lens prescription you need. That’s a decision for your optometrist or ophthalmologist to make based on the results of your eye exam. You just show up, get evaluated, and sent along with a prescription.
You may not get to choose the type of lenses that you need. However, you’ll surely want to know what you’ll be paying for. After all, glasses are often an investment unless you decide to buy online!
Single Vision Lenses
Single vision lenses are the most basic type of lens. Unsurprisingly, they also tend to be the least expensive. Made for correcting one field of vision (near or far), they offer the largest visual field of any lens type.
If you’re only short-sighted or long-sighted, you’ll likely be prescribed single vision lenses.
Photochromic (Transition) Lenses
Also known as “transition lenses,” photochromic lenses darken when they come into contact with UV rays. This eliminates the need for sunglasses, increasing convenience and minimising expense for the wearer.
They’re technically not a prescription type, but rather a treatment added to prescription lenses. You can have photochromic bifocals, single vision lenses, and so on.
Note that the lenses will darken even on cloudy days, which some may find inconvenient. However, they’re often a popular choice as they add a little style to your glasses.
Bifocal & Trifocal Lenses
You probably remember your grandfather wearing these. This is because these lenses correct a wider range of more severe vision issues. Bifocals and trifocals are lenses that have two and three “powers” apiece, respectively.
They are sometimes referred to as “multifocals” even though this technically refers to progressive lenses.
All within one lens, you have separate sections for near and distance correction, which makes them a versatile choice. Those requiring intermediate vision correction will be prescribed with trifocals that have a third correction too.
The drawback of bifocals and trifocals is that there are lines separating each section, which makes for drastic changes in vision correction when you move your eye inside the lens. It’s something that you learn to work with, but the inconvenience paved the way for advances in lens technology such as progressives.
Progressive lenses perform the same job as bifocals and trifocals, but in a different way. They work around the dividing lines of bifocals, which was a known inconvenience glasses wearers dealt with for many years.
Overall, progressive lenses offer the same fields of vision correction but without the lines. Transitions from “near” to “intermediate” to “distance” correction are much smoother.
The downside? The actual visual field within progressive lenses is smaller than that of bifocals or trifocals. This may help to explain why we still see many older folks wearing trifocals as opposed to progressive lenses.
Screen Or Computer Lenses
Whilst these are the newest invention in eyewear, it’s not technically correct to refer to computer glasses as “prescription” lenses. We listed them here anyway because they’re becoming increasingly ubiquitous.
Use of electronic devices has increased dramatically, and it’s hurting our eyes. Raw percentages of glasses wearers have increased greatly since smartphones and computers became part of our daily lives, and we are at great risk for accelerated macular degeneration, the leading cause of vision loss.
These devices emit blue light, certain ranges of which are harmful to our eyes. Computer glasses filter out this blue light, minimizing general eye strain and fatigue, reducing headaches, and generally keeping your eyes healthier.
Computer glasses are sold without prescriptions (sometimes as yellow-tinted glasses), and many companies will offer a blue light-blocking lens coating that performs the same function, but with your current prescription.
If you spend much of your day in front of one of these devices (we know that you’re more likely than not reading this on your smartphone), talk to someone about making your glasses computer-friendly.
As we said above, you will not be in control of the type of prescription you get, but it’s still good to know what you’re spending money on.
You can, however, control many other aspects of your glasses, and we have a few different guides to help you pick the best glasses for you. We recommend the following guides to help find the best glasses online: