How to use online eye exams and vision tests to get a glasses prescription

Making time to catch the latest Netflix hit? Easy. Making time to visit the eye doctor? Surprisingly difficult. Enter: Online eye exams — because if you can do it from your couch, why wouldn’t you? Thanks to ever-advancing technology, you can now go to your favorite eyeglass retailer's website, take a quick online vision test and — voila! — you have an eyeglass prescription ready just as your next episode queues up.

While it sounds like seemingly great news for the 70% of Americans who wear prescription glasses — especially the 27% who haven't visited their eye doctor in over 3 years — is it actually a good idea to skip an in-person eye exam for online convenience?

In this article, experts explain who might benefit from an online vision test, who should stick to in-person exams and what you need to know before clicking ‘start test.’

What are online vision tests?

In 2022, fresh from our collective Zoom-everything era, the Food and Drug Administration gave clearance to Visibly — a web-based, self-guided software app that lets folks between the ages of 22 and 40 evaluate their visual acuity at home in about 6 minutes. "Visual acuity" is a fancy way of describing how sharp or clear your vision is, explains Dr. Annie Nguyen, MD, an ophthalmologist at the University of Southern California Roski Eye Institute, part of Keck Medicine of USC.

While Visibly is the first digital vision test to receive FDA clearance, similar applications have been around since 2014. The basic concept remains the same regardless of platform: You take a read-the-eye-chart test at home, and an eye doctor reviews your results to determine if your current prescription is still OK. If it is, you'll get your renewed prescription pronto. However, if your vision has changed, they'll recommend a comprehensive eye health exam instead.

How do online vision tests work?

"During an online vision test, you'll use a smartphone, tablet and/or computer to assess your visual acuity by following a series of prompts, like reading letters on a screen that decrease in size," explains Nguyen.

Much like an in-person exam, maintaining the correct distance of 10 to 20 feet from the screen is crucial. However, accuracy depends on the user since the test is self-administered and unsupervised. "You need to ensure correct distance and appropriate lighting. If those factors are off, it'll affect the accuracy of your results," Nguyen warns. Once the test is completed, an eye care professional reviews the results and either approves your prescription renewal or recommends an in-person exam for further evaluation.

Who can use online vision tests?

To qualify for an online vision test, you must meet certain eligibility criteria, which can vary by provider. Common requirements include:

• Residency: You must live in one of the 35 eligible states.

• Age: You must be within the age range required by the brand. For example, Visibly is for individuals aged 18 to 55, while Warby Parker accommodates a wider range of 18 to 65.

• Eye health: Your eyes must be generally healthy, with no conditions that could affect your vision, such as diabetes or glaucoma.

• Prescription: You need a current single-vision distance prescription.

• Technology access: You must have a compatible device, such as a computer and/or an iPhone 6s or newer.

Even if you meet these requirements, online eye tests aren't right for everyone. "Home vision exams are best used to update an existing mild to moderate eyeglass prescription in adults who have previously gone in for a comprehensive eye exam," explains Dr. Shivani Kamat, MD, assistant professor of ophthalmology at the University of Texas Southwestern Medical Center. She adds, "You should also be free of any eye disease symptoms."

Experts recommend skipping online testing if you regularly experience:

• Eye pain or irritation

• Eye fatigue or strain

• Changes in eye function, such as excessive tearing

• Changes in eye appearance, including yellowing or redness

• Changes in eye movement or alignment

• Double, blurred or tunnel vision

Online eye exams: What are the advantages?

There are several benefits of online vision tests. "They definitely provide a convenient and affordable option for many people," says Nguyen. "And that's especially true for those who might otherwise not have access to an eye doctor." And, it turns out, that's a whole lot of people.

One report found that over a quarter of U.S. counties have no practicing eye care providers. The hurdle is even higher for Medicare patients, with fewer than seven eye care professionals serving every 10,000 beneficiaries.

Even in well-served areas, roughly 63% of Americans don't have vision insurance. This means they're shelling out around $200 for an in-person eye exam — and that's before tacking on the price of glasses. On the flip side, Warby Parker's online vision test, for example, costs just $15.

Beyond price and convenience, "Online vision tests can be a helpful tool for individuals with mild refractive errors, those who just want to check their vision periodically, and for people who are monitoring a stable prescription and just want a quick check to see if their vision has changed," explains Nguyen.

What are the drawbacks of online eye exams?

There are some significant differences when you compare an in-person eye exam to its online cousin. For example, "There are 12 important tests performed during an in-person eye examination, but online vision tests attempt to replace just one of these elements, which is refraction," explains optometrist Dr. Steven Reed, OD, president of the American Optometric Association (AOA). He notes that refraction determines the lens power required to compensate for any refractive error, like nearsightedness or farsightedness.

If you're simply looking to get new glasses, that might not seem like a big deal, but experts warn that it can be. "It's important to remember that online vision tests focus solely on prescription numbers, not signs of eye disease," says Kamat. "This is a problem because some of the leading causes of blindness, such as glaucoma and diabetic eye disease, can begin without any noticeable symptoms."

If you wait to experience changes to your vision before you make an appointment with an eye doctor, eye diseases may remain undetected and untreated. One of Reed's biggest worries? "Online vision tests can give patients a false sense of security that their eye health has been thoroughly examined when it's not," he says.

Why in-person vision tests remain important

Even if your vision seems crystal clear, the AOA recommends scheduling an annual in-person eye and vision exam for all adults aged 18 to 64. This is especially crucial as you approach 40, as this is when many eye diseases begin to develop. "[In-person eye exams are] also particularly important for folks with a history of eye conditions, those who experience sudden vision changes and those who belong to higher-risk groups, like those with diabetes," says Nguyen.

Not only is a comprehensive eye exam much more accurate than any home vision test, but your eye doctor looks out for issues beyond vision. "Full in-person eye exams include tests for conditions like glaucoma, cataracts, macular degeneration and retinal diseases — and that requires specialized equipment that simply cannot be easily replicated remotely," notes Nguyen.

"Ophthalmologists are medical doctors," explains Kamat. "We're trained to spot changes to your eye health — and sometimes we can even detect underlying health issues elsewhere in your body." These once-a-year once-overs don't just keep your vision sharp — they catch subtle eye changes and spot early warning signs of both eye and overall health conditions before they become serious. "Remember, most eye diseases are best treated in early stages, which means regular in-person eye exams are your best course of action," adds Kamat.

Bottom line: Should you try an online vision test?

There's no denying that updating your prescription while still in your pajamas sounds enticing. However, online vision tests aren't a replacement for comprehensive, in-person exams. Eyeglasses are medical devices, not just fashion statements, reminds Reed, so skipping steps in the process could affect your health. Before you order new glasses online, it's critical to understand what these digital services can't do: Detect eye diseases, spot early warning signs of health conditions and ensure your prescription is optimal for your specific needs.

Does this mean you should skip the digital option? Not necessarily. Nguyen notes that telemedicine is "a valuable complement to traditional care," making life easier for people who struggle to reach an eye doctor. But there's a reason in-person eye exams remain a must: "Right now, online vision screening services aren't required to meet the same criteria as a comprehensive eye exam, which means you could miss crucial health diagnoses," says Reed. So, while virtual vision tests might save you time today, scheduling an in-person eye exam is key for keeping your eyes healthy long term.

FAQs

Are online eye exams accurate?

While they may help assess vision in people with mild to moderate prescriptions, online eye exams are not as accurate as a comprehensive in-person eye exam. "People with significant uncorrected nearsightedness, farsightedness, astigmatism or presbyopia may find it difficult to accurately complete the test," says Nguyen. "It's also important to remember that without a professional on hand, there's a higher risk of improper test conditions, like incorrect distance or poor lighting, which could affect the accuracy of an online vision test."

Who should use online eye exams?

"Home vision exams are best used by adults who want to update their existing prescription and have already had a comprehensive eye exam," says Kamat. "Just remember to use these online vision tests only if you're a healthy adult with a mild to moderate prescription and no eye health concerns." While the appropriate age range for these types of vision tests varies among providers, Kamat suggests limiting it to those between 18 and 39.

What is the difference between an online eye exam and an in-person eye exam?

Perhaps the most important difference is the lack of an in-person eye doctor to "assess other potential eye health concerns — or provide a complete diagnosis," says Nguyen. Additionally, online vision tests are not standardized or as comprehensive as in-person eye exams.

When you go in for a traditional vision test, everything is standardized, which minimizes the chance of error. "That means the lighting and visual presentation is controlled — and so is the distance you are from the Snellen chart," says Nguyen. That's the familiar test usually featuring 11 rows of capital letters, with an increasing number of letters that are smaller in size in each row.

You take your glasses off or contacts out, then peer through a special device called a Phoroptor or refractor and focus on an eye chart 20 feet away. The eye doctor then asks if the chart appears clearer when different lenses are in place. "Your eye care professional may use more advanced testing devices, too, such as automated refraction instruments," says Nguyen. Here, the machine shines a light into the eye and measures how it changes as it bounces off the back of the eye. "If any issues arise during an in-person exam, a health care provider can offer immediate feedback, suggest further testing or make treatment recommendations," says Nguyen.

An online visual acuity test is, essentially, an at-home version of the Snellen chart. Instead of looking through a Phoroptor, you look at a series of prompts, like letters that decrease in size, on your smartphone, tablet or computer. "The test is often conducted from a specific distance, but you administer the test yourself, so you're responsible for following the test instructions correctly," says Nguyen. "Without a professional on hand, there's a higher risk of improper test conditions, like incorrect distance or poor lighting, which could affect the accuracy."

Can I get a prescription for contact lenses with an online exam?

Yes, you can renew a contact lens prescription with an online vision exam — but should you? "No," says Kamat. "Contacts should be fitted by an ophthalmologist or optometrist who's trained to check for a good fit. Improperly fitting contact lenses can cause complications, from redness and irritation to potentially blinding eye infections." In fact, the American Academy of Ophthalmology clearly states that consumers should "never use home vision tests to order contacts."

Meet our experts

• Shivani Kamat, MD, assistant professor of ophthalmology at the University of Texas Southwestern Medical Center

• Annie Nguyen, MD and ophthalmologist at the University of Southern California Roski Eye Institute, part of Keck Medicine of USC

• Steven Reed, OD, optometrist and president of the AOA

Our health content is for informational purposes only and is not intended as professional medical advice. Consult a medical professional on questions about your health.