Outcomes and methods
A number is only as good as its definition. Here is each of the numbers we report most often, how it is defined, and what it leaves out.
- Count people, not activity. We report how many people could see, travel or work afterwards, not how many workshops we held.
- Fix the definition before the year starts. Each indicator and its target are set in March for the year ahead and not changed after the results are in.
- Report the people we lost. Where some people are not followed up, we say how many, and from FY2025 we estimate what their outcomes probably were.
- Check a sample ourselves. Our programme quality team visits a random sample of partners each year without warning and re-measures a sample of patients.
- Publish the data. Hospital-level and partner-level data for our two largest programmes is downloadable below.
Headline indicators
| Programme | Indicator | Definition | FY2025 | FY2024 |
|---|---|---|---|---|
| Sight restoration | Good outcome after cataract surgery | Presenting acuity 6/12 or better in the operated eye, 4 to 8 weeks after surgery, of patients followed up | 78.4% | 77.6% |
| Sight restoration | Follow-up rate | Share of patients seen at 4 to 8 weeks | 71.2% | 70.4% |
| Mieru | Spectacle wear | Wearing or carrying spectacles at an unannounced visit 3 months after delivery | 58% | 57% |
| Mieru | Time to spectacles | Median days from screening to delivery | 24 | 27 |
| Implant safety | Days to signal | Median days from first report in a pattern to a published signal | 19 | 20 |
| Implant safety | Clinician review | Share of reports read by a clinician within 2 working days | 96.1% | 94.8% |
| Continuity | Devices kept working | Share of repaired devices still working 12 months later | 88.3% | 86.0% |
| Living with low vision | Independent travel | Assessed as able to travel alone on a regular route after training | 74% | 71% |
| Living with low vision | Work retained | In paid work 12 months after placement | 87% | 84% |
| Shared Sight | Deletion on request | Deletions confirmed in writing within 30 days | 100% | 100% |
FY2025 is 1 April 2025 to 31 March 2026.
Source: Programme returns, audited by the programme quality team, Nairobi.
- Sight restoration, by hospital (CSV) All 41 partner hospitals, FY2021 to FY2025: operations, follow-up and outcomes.
- Mieru vision screening, by partner (CSV) Twelve partners, FY2021 to FY2025: screening, referral, spectacles and wear checks.
Rows in each file add up to the totals on the programme pages. Data for the other programmes is published in summary on their pages.
Estimating what we cannot see
About three in ten cataract patients do not come back for their follow-up visit, and the reasons are not random: people with a poor result are less likely to return to the hospital that gave it to them. If we report outcomes only for people who come back, we flatter ourselves.
From FY2025, our programme quality team traces a random sample of patients who missed follow-up, at home, and measures their sight. In FY2025 they traced 1,214 people across fourteen hospitals. Of these, 69.8% had a good outcome, against 78.4% of those who came back. We use the difference to give a range for the true share of good outcomes, which for FY2025 was 72% to 78%.
Tracing is expensive and slow, and we do it only for sight restoration so far. Mieru will begin tracing children who were referred but did not reach an optometrist in FY2026.