VisionSpring sold reading glasses door to door, skipping the eye exam

Jordan Kassalow, an optometrist, encountered the scale of the problem directly during a vision-screening trip to Mexico's Yucatan Peninsula, where a boy who appeared to have a learning disability turned out simply to need corrective lenses. Presbyopia, the age-related loss of near vision that typically begins around 40, is one of the most common and cheapest-to-correct vision problems worldwide, yet it went undiagnosed and uncorrected for hundreds of millions of low-income adults.

The conventional response -- clinics offering individualized eye exams followed by custom-fitted glasses -- could never reach that population at scale: credentialed optometrists were structurally scarce in rural and low-income regions, and a custom pair of glasses cost far more than a day's wages for people earning around $4 a day. Kassalow founded the Scojo Foundation (later renamed VisionSpring) in 2001 to test a different starting assumption: that most presbyopia correction did not need a clinical process at all.

skipped exam, sold pre-set diopter glasses door-to-door

Presbyopia needs only a few standard diopter strengths, not custom prescriptions.

Skipping the exam removed the dependency on scarce optometrists.

Mass-produced glasses cost a dollar or two, affordable for low-income buyers.

Local women sellers used existing informal commerce channels, scaling distribution.

When a scarce professional bottlenecks a service, check if most customers need only a few standard variants; if so, strip the individualized step and sell them as a commodity via informal channels.

A 2018 Lancet Global Health RCT found tea pickers given reading glasses picked 21.7% more, some over 30% more.