The strongest evidence comes from randomized controlled trials. PROSPER, a trial among tea pickers in Assam, India, found that reading glasses raised daily productivity by 22%, rising to 32% for workers over 50. THRIVE, a trial among workers in vision-intensive jobs in Bangladesh, found median monthly incomes rose roughly 33% for first-time wearers.

A follow-on trial, PROSPER II, extended the finding to garment factory workers, where the gains from wearing glasses was about two-thirds as large as the gap between the highest and lowest skill grades on the factory floor.

In 2024, GiveWell granted $4.8 million to the London School of Hygiene & Tropical Medicine for the EARN trial – a 20,000-person RCT in India and Kenya designed to resolve remaining cost-effectiveness uncertainties and measure the effect of eyeglasses on household consumption and vision-related quality of life among working-age adults. The study is in progress.

Multiple studies find that people with uncorrected near-vision loss often experience worse physical health, increased rates of depression, and lower overall quality of life.
(Goertz et al., Tahan et al., Reyes-Ortiz et al.,  Lu et al., Tseng et al.)

We track first-time wearers as a distinct metric alongside total distribution, so we can see whether growth is reaching new people or re-supplying existing wearers. Partner dashboards report both. To date, our partners have distributed roughly 3.3 million pairs across 20 countries.

In Nigeria, where 1.5M people were screened and 1.3M people received reading glasses through the primary health system in under 12 months, a remarkable 66% of all beneficiaries received their first-ever pair of glasses.

Glasses are transformative.

Cohort studies across India, Pakistan, and Sierra Leone, show that nearly 90% of recipients still wear their glasses years after receiving them, and most pay out of pocket for replacements. The 2025 study in India, Seeing Beyond the First Pair, found 93% still wearing glasses five years on, and 61% had bought at least one replacement pair from a private optical shop.

Yes, in Ethiopia, Nigeria, India, Uganda, and Kenya, basic eye care and glasses distribution are being embedded into existing health systems–with many more countries in the pipeline. 

In Ethiopia, the Ministry of Health (MOH) has integrated these services into non-communicable disease (NCD) services carried out by community health workers. The Ethiopian MOH and the Ministry of Finance now actively support the tax-exempt importation of eyeglasses, a big win in lowering commodity overhead and establishing a fiscal foundation for long-term sustainability.

In Nigeria, over 1 million glasses have been dispensed through primary health care facilities. 10 state governments are now funding their own scaled programming.

In India, reading glasses are being deployed through government-led community-based networks, including Community Health Workers (CHWs) and primary health facilities. Some states are funding the pilots, supported by partners, before scaling.

In Uganda, we are supporting Village Health Teams (VHTs) — Uganda’s nationwide community health worker cadre — to screen and dispense reading glasses via door-to-door visits.

In Kenya, basic eye care, including vision screening and the distribution of reading glasses, is being embedded into public health facilities and CHW services through two county-wide pilots, with aims to expand to all 47 counties.

We track activation in every geography — the government approvals, protocols, and materials needed to launch screening and distribution — and whether the resulting data is reported into national health information systems rather than held in donor-run databases.

The leading indicator is whether people buy replacement glasses at full price, and long-term consumer studies (above) show most do. 

In India, 93% of recipients were still wearing glasses 5-6 years later, and 61% were using a replacement pair, purchased at an average cost $7.70 – or 162% of participants’ daily wages. This indicates willingness to make a significant investment for clear near-vision. Most replacements were purchased from private optical shops (68%), followed by health facilities (29%).

We also fund research to strengthen the market itself. In Bangladesh, behavioral insights work on sales-based delivery models raised glasses sales at vision camps by 185% within two months.

Through pilots and iterations of multiple delivery channels over the last 3.5 years, Vision Action Fund finds that integrating into existing systems–health systems, community-based networks, and private sector markets–are the most cost-effective approaches to delivery. As these channels scale, the unit economics improve.

The EARN trial, is also designed to resolve remaining cost-effectiveness questions across delivery channels.