Methods and systems for producing a refractive prescription for a consumer away from an optical office are disclosed. At a first time point, a first prescription for a first pair of corrective lenses is generated according to measured refractive errors, and a historical visual acuity profile is measured using the first prescription and a varying spherical power. At a second time point, a second visual acuity is measured using the first prescription. A new spherical power is computed using the historical visual acuity profile and the second visual acuity. A second prescription for a second pair of corrective lenses is generated based on the first prescription and the new spherical power. In some embodiments, the second visual acuity may be self-administered by the consumer away from an optical office.