Warby Parker may be known for their eyeglasses, but many of their retail locations provide eye exams too. These tests are used to update your vision prescription, the set of measurements used to make custom eyeglass lenses.

Warby Parker offers three kinds of eye exams:

• In-store eye exam – Going by the literal definition of an eye exam, this is the only one Warby Parker offers. A licensed eye doctor will check the health of your eyes and update your vision prescription.

• In-store Prescription Check – An eye doctor will check your eyesight and renew your existing prescription if needed.

• Online Prescription Check – An automated app will determine your vision prescription.

These options might sound similar, but they are different in a few important ways.