Do you have trouble seeing objects that are up close, far away, or both? If so, you’re not alone. Nearly 75 percent of adults across the globe require some sort of vision correction in the form of glasses, contact lenses or both.
In this article, we’ll be focusing on the most common form of vision correction: prescription glasses. How do prescription glasses work? How do you read a glasses prescription? How do you go about ordering prescription glasses? We’ll be answering those questions and many more today.
Let’s get started.
Prescription Glasses Basics
Prescription glasses help people see the world clearly and can be used to correct just about any vision-related condition. Unlike non-prescription reading glasses that can be purchased over-the-counter, people must consult an eye doctor to obtain an accurate prescription that will alleviate their visual problem.
When were prescription glasses invented?
While it’s hard to imagine that people had to live with uncorrected blurry vision, the first pair of eyeglasses weren’t invented until the 13th century in Italy. These glasses were not nearly as advanced as what we have today and were essentially comprised of two magnifying glasses connected by a bridge.
Over the next several hundred years, many advancements were made to this technology, including developing different lenses for nearsightedness and farsightedness and the addition of frames to allow the glasses to stay on the face.
In 1799, America’s first practicing optometrist, John McAllister, opened the first optical shop in Philadelphia.
Why would a person need prescription glasses?
Most vision issues addressed by prescription glasses fall into the category of refractive errors, which happens when the eye cannot properly focus light onto the retina. As a result, the image sent to the brain is distorted and blurred.
Refractive errors fall into four main categories:
- Myopia (nearsightedness): Far-away objects appear blurry
- Hyperopia (farsightedness): Nearby objects appear blurry
- Astigmatism: Can make far-away and nearby objects appear blurry or distorted.
- Presbyopia: Makes it harder for middle-aged and older adults to see things up close.
What do prescription glasses do?
Glasses with prescription lenses correct refractive errors by allowing the eye to focus light in the right spot on the retina. Because everyone’s eyes are different, a pair of prescription glasses that enable one person to see clearly may blur someone else’s vision. This is why prescription glasses require a personalized prescription from an eye doctor.
In this case, a prescription doesn’t mean medicine you’ll pick up at a drugstore, but rather a piece of paper with numbers on it. These numbers indicate the specific curvature and dimensions the lenses need to be to allow a person to see clearly.
How do you read glasses prescriptions?
After visiting your eye doctor for an eye exam, you’ll receive your prescription, either on a piece of paper or digitally. It will probably look like a small grid or chart with numbers, letter abbreviations, and positive and/or negative symbols. What do they all mean?
Here’s a breakdown of the most common eye prescription abbreviations, numbers, and symbols in simple terms:
- OD: Your right eye.
- OS: Your left eye.
- OU: Both of your eyes.
- NV: Near vision (seeing things close-up).
- DV: Distance vision (seeing things far away).
- PD: Pupillary distance (the distance between your pupils).
- SPH: Sphere, or the strength of magnification in the lenses.
- CYL: Cylindrical correction, or the amount of lens power needed to correct an astigmatism.
- Diopters: Any numbers you see in the columns are called diopters—a measurement of the refractive power of a lens. You’ll see larger numbers if your prescription requires more optical power and lower numbers if your vision doesn’t need as much visual support.
- Negative signs: If you see a minus sign (-) in front of a number, that indicates nearsightedness. Someone with -3.00 diopters of nearsightedness, for example, will likely have trouble reading words on a whiteboard from far away.
- Positive signs: If you see a positive sign (+) in front of a number, that indicates diopters that will correct farsightedness. Someone with +3.00 diopters of farsightedness, for example, will likely struggle to read text that’s very close to their face.
While it helps to understand what your prescription means, you don’t need to understand it fully. All you need to do is present your prescription when you buy prescription glasses at a store or online so that the manufacturer can insert lenses with the proper level of correction.
Are glasses and contact lens prescriptions the same?
Many people wonder if they can use their glasses prescription to order contact lenses. The answer is no. While they both have the same objective—correcting refractive errors—they are distinctly different.
The main reason for this is because contacts sit directly on your eyes, while glasses sit about 12 millimeters away from your eyes. This difference might seem minor, but it requires two different tests and yields two different sets of measurements. As such, the numbers on your glasses prescription may be significantly different from those on your contact lens prescription.
What is the highest prescription for glasses?
On an eye prescription, 0.00 represents good vision that doesn’t require correction. The further away from zero (+ or -), the worse a person's eyesight is. A number between +/-.025 and +/-2.00 is considered mild, a number between +/-2.25 and +/- 5.00 is deemed moderate, and a number greater than +/- 5.00 is said to be severe.
Generally speaking, +/- 30.00 is the limit most optical labs can accommodate. However, diopters this high are unusual.
Can glasses stop working?
If you’ve been wearing prescription glasses successfully for a while and they suddenly seem like they’re not working anymore, that’s a sign your vision has worsened. The glasses themselves haven’t changed, but your vision has.
In this case, you’d need to return to your eye doctor for another eye exam. You’ll likely need a new prescription that addresses your vision change and, consequently, new lenses put into your glasses.
How often should I get new glasses?
There’s no hard and fast rule of how often you should get new glasses. If your vision hasn’t changed and your glasses are in good condition, you may be able to keep the same pair for many years with one caveat: you should see your eye care provider yearly to check not only your prescription, but your ocular health. Seeing your eyecare provider regularly ensures that your eye is healthy and that you are in the most up to date prescription.
The Investment for Prescription Glasses
Now that you’re more familiar with the ins and outs of prescription glasses, you’re likely wondering how much a pair costs. Let’s find out.
What is the average price for a pair of prescription glasses?
The cost of a pair of prescription glasses varies significantly based on several factors, including your prescription, the type of frames, the type of lenses, the region you live in, and the brand.
According to Consumer Reports, prescription glasses from a discount retailer have a median out-of-pocket cost of $184, while prescription glasses from a top eyewear chain have a median out-of-pocket cost of $369. Designer glasses can cost up to $1,000.
If you have an insurance policy that covers prescription glasses, the cost could be significantly lower. Most insurance companies will pay about $120 towards a pair of prescription glasses.
Is it cheaper to buy prescription glasses online?
You can also save a significant amount of money by purchasing your prescription glasses online. Consumer Reports found that shoppers saved as much as 40 percent by buying glasses online.
Buying Prescription Glasses Online
In addition to being less costly, buying prescription glasses online comes with many benefits. It is convenient, expands your options, and saves you time. So, what exactly do you need to buy prescription glasses online? Here’s what you need to know.
What information do you need to buy glasses online?
First, you’ll need to visit an eye doctor to receive a personalized prescription. This process cannot be done online. However, once you have your prescription in hand, it’s smooth sailing.
Simply explore different frame styles online until you find the ones you like best. During checkout or after purchase, you’ll be asked to upload or email your prescription to the retailer so they can craft your lenses with your unique specifications. Your prescription should contain all of the information the manufacturer needs to create your lenses.
What other considerations are there for purchasing prescription glasses online?
Beyond your technical prescription, the types of lenses you choose are important to achieve your desired results.
Online retailers offer several different types of lenses to meet different vision needs. At GUNNAR, we offer our prescription blue light glasses with the following types of lenses:
- Single vision: These lenses are the most common and have one corrective power.
- Progressive: These lenses have multi-focal lenses for people who need corrective lenses to see distant and close-up objects.
- Progressive Computer: These lenses are meant to be worn in an office environment. They’re best worn while doing computer work or in a conference room up to 14 feet. They’re not meant for seeing at long distances.
Prescription Blue Light Glasses
Blue light glasses are becoming increasingly popular these days—and for good reason. They help reduce your exposure to harmful blue light emitted from digital screens.
Excessive exposure to blue light via screens has been shown to inhibit the production of melatonin—the sleep hormone—which can make it difficult to fall asleep or stay asleep. Research also shows that blue light may damage retinal cells, potentially leading to macular degeneration.
Additionally, prolonged screen time can cause symptoms of digital eye strain, including headaches, dry eyes, and blurry vision. The combined result is tired, irritated eyes and poor sleep.
Can you get blue light glasses with a prescription?
For those who need prescription glasses but also want to protect their eyes from the adverse effects of prolonged screen time described above, there’s an easy solution: prescription blue light glasses. These glasses have special tinted lenses designed to filter out blue-violet light rays emitted from digital screens.
The lens technology used for GUNNAR prescription blue light glasses not only blocks from 35 to 98 percent of blue light (depending on the type of lens you choose), but also reduces glare and addresses all short- and long-term side effects of digital eye strain, including headaches, dry eyes, blurry vision, eye strain, and eye fatigue. Click here to learn more about GUNNAR prescription blue light glasses.
Should I wear my glasses while using my phone?
The beauty of prescription blue light glasses is that you can wear them when using any type of digital device, from your smartphone to your computer. Doing so will not only allow you to see clearly, but will also protect your eyes from blue light and other effects of prolonged screen use.
Whether you use technology most of the day for work, frequently get lost in long gaming sessions, or enjoy binge-watching your favorite shows, blue light lenses can help mitigate the effects of blue wavelengths from digital devices.
The Bottom Line on Prescription Glasses
There’s nothing quite like putting on a new pair of prescription glasses. They instantly transform the world from distorted and blurry to clear and defined.
The process of getting prescription glasses starts with getting an eye exam from an eye doctor. Once you have your prescription, you’re ready for the fun part: buying a pair of prescription glasses that fit your unique style and needs.
GUNNAR offers numerous styles of prescription blue light glasses, each with unique features that cater to different needs. Everyone from the avid gamer to the sophisticated executive is sure to find their perfect match within our collection. Find your style today!