Okay, so it’s been a while since you’ve checked in with your eye doctor—either you never get around to making an appointment, or something comes up at work and you have to cancel, or you don’t have the coinage to pay for an exam, let alone a new pair of Warby Parkers.

If you’re feeling guilty about ghosting your optical health, you can now breathe a little easier: Thanks to a new service called Opternative, you can score an accurate and affordable eye exam from the comfort of your own home. All you need is your smartphone and a computer. (No, but seriously.)

With eye exams costing an average of $85 a pop (not to mention the stuffy waiting room vibe that comes with them), Opternative is a super-intriguing option for the cash-strapped, time-crunched 18- to 40-year-old demo—but how exactly does it work?

First, you head over to Opternative’s website and answer a few eligibility questions (such as when you were last tested and if you have any eye conditions). You then calibrate your screen for the exam, and sync your phone as a remote for your computer using Wi-Fi and an SMS confirmation. Finally, you take the test, which consists of a series of dictated and written instructions that you answer using your phone.

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The exam takes about 25 minutes, at which time you can pay to have Opternative review your results and send you a physician-issued prescription for glasses or contacts within 24 hours. The cost is $40 for a glasses or contacts prescription, or $60 for both. Best of all, you can use the prescription to get glasses or contacts anywhere, including online outlets like Warby Parker or 1-800-Contacts.

As for accuracy, a clinical trial that compared the Opternative eye exam to a traditional refractive exam found the online test results and subsequent prescription were just as accurate. That said, the company does stress its service is not meant to replace your eye doctor, and you should still check in with your doc at least once every two years.

So where might a service like this fit into your overall eye care routine—and how “okay” is it to cheat on your eye doctor? “I don’t think most eye doctors would consider this cheating,” says Robert Noecker, an ophthalmologist with the Ophthalmic Consultants of Connecticut. “It allows people who are healthy to get an eyeglass prescription quickly, and allows us to spend time with more complicated patients who need more attention and probably have medical issues.”

If you do decide to use the service, Noecker suggests having at least one eye exam under your belt so that you can use your old prescription as a comparison. “If you’re just squinting when looking at street signs or sitting in the back of the movies or classroom, I think this site can be a good place to start,” says Noecker, who isn’t affiliated with the service.

The process does require a bit of precision though, so if you don’t have the space to get far enough away from your computer or aren’t good with detail, the service might not be a good fit—you might need someone there with you to get an accurate result. But if you only need a mild(ish) prescription and are detail-oriented, or if your current glasses prescription is set to expire and you don’t have time to fill it, Opternative could very well be the cheese to your (wallet’s) macaroni, says Noecker.

Opternative is currently available in 27 states, with more expected soon.

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