You might not have to visit an optometrist just to get a basic prescription update for your glasses. Warby Parker is trotting out Virtual Vision Test, a revamp of its Prescription Check app that lets you renew your glasses or contact lens prescription using only an iPhone and your existing eyewear. Prop up your phone, stand 10 feet away and you can walk through a familiar “can you read this” test that will gauge whether or not your glasses or contacts need updating.

The update isn’t automatic. An eye doctor will review the results and give you a verdict within two days. If you’re seeing well enough, you’ll just need to pay $15 to renew your prescription. If you’re either struggling or just aren’t eligible to use the app (see below), Warby Parker will recommend that you get a thorough eye exam.

The company is clear that this isn’t a replacement for your eye doctor, and that you’ll have to meet certain criteria beyond what we just mentioned. You have to be between 18 and 65 years old, with no existing eye health concerns and a single-vision distance prescription.

The approach relies on iOS’ Vision Framework to measure your distance from your iPhone and ensure that you’re far enough away from a proper test. We’ve asked Warby Parker about an Android version, although that might take a while given that it would need a rough equivalent to Vision Framework.

The motivations behind Virtual Vision Test are clear — on top of the renewal fee, this could lead to more people buying Warby Parker glasses and visiting the company’s stores. Regardless, it could be very useful if you either can’t make time to update your prescription or are still skittish about a visit while COVID-19 remains a concern.