Blindness is often viewed solely as a public health issue or as a set of personal losses, such as reduced independence or the inability to enjoy the everyday moments in life.
However, less attention is paid to its economic consequences. When vision is lost, the effects reach far beyond the individual, as income falls, labour participation declines, and households face greater economic strain.
Across a developing economy like Tanzania, these hidden losses can accumulate significantly. Cataracts are one of the leading causes of avoidable blindness worldwide, directly affecting approximately 94 million people.
While cataracts can affect people of all ages, most people experience cataract-related vision impairment at ages 50 and older (World Health Organization, 2026a).
This loss of vision undeniably contributes to a decline in the quality of life of the impaired individual, affecting several interconnected factors, including their independence, their social and mental well-being, and their employment and productivity (World Health Organization, 2019).
With the loss of independence, family members are regularly required to step up as caregivers, placing demands on time that might otherwise be spent on work, education, and other productive activities (Köberlein et al., 2013).
As a result, cataract blindness not only diminishes the economic capability of one household member, but can limit the contribution of two (Polack et al., 2010).
Despite the ongoing economic challenges posed by cataract blindness, the condition is easily treatable, with a single surgery providing immediate and lasting restoration of sight.
Cataract surgery is relatively low-cost to deliver, particularly when performed at scale in lower-resource settings (Malcolm & Bako, 2022). The procedure is short, averaging only 15 minutes, performed painlessly and as an outpatient procedure (Cleveland Clinic, 2023).
However, treatment remains limited. In Sub-Saharan Africa, the World Health Organization reports that “one in two people who need cataract surgery remain untreated” (World Health Organization, 2026b).
This gap can be attributed to barriers such as cost, distance, and limited services, all of which are linked to structural poverty, especially in Tanzania. Even when access is available, gaps persist due to patients’ lack of awareness and understanding of their condition and its intervention (Sandi et al., 2024).
With the large unmet need and inexpensive intervention, there is a major unrealized opportunity. Greater investment can help overcome these barriers, creating benefits that extend beyond restoring sight.
In a study that evaluated the economic impact of cataract intervention, patients who received surgery reported several lifestyle changes related to their economic productivity (Rabiu et al., 2023). For instance, 96.2 percent of beneficiaries reported an increase in general productivity, whilst 99.6 percent reported an increase in income.
Additionally, 99 percent reported improvements in employability and 97 percent in skills. When delivered at scale, these individual outcomes contribute to a healthier, more productive and skilled workforce, strengthening household incomes and supporting broader economic development.
Outcomes like these demonstrate why cataract surgery should not be viewed solely as a health intervention, but as an investment. In traditional business models, the return on investment measures the value generated relative to the initial expenditure.
In the case of cataract surgery, the initial investment is relatively small, but its value is continuous. This broader return is reflected in our own programme data. Between January and June of this year, the Mo Dewji Foundation delivered 12 mobile eye camps, performing 4,238 cataract surgeries.
An internal Social Return on Investment (SROI) analysis using data from these camps assigned financial value to outcomes including restored productivity, caregiver time freed, resumed schooling and avoided public health costs.
Though SROI analyses rely on financial proxies, as these outcomes are inherently difficult to monetise, sensitivity testing allows the estimates to be assessed under varying assumptions.
Our analysis estimated that every $1 invested generated approximately $7.62 in social value, with the return remaining at approximately $6 per $1 even under conservative assumptions.
At the Mo Dewji Foundation, our commitment to maximizing impact is central to the ethos of our organization, guiding our approach to program development. When choosing which causes to focus on, we are driven by both the identification of critical issues in Tanzania and the rigorous assessments of which interventions create the most impact per dollar.
The economic benefit garnered through cataract blindness restoration is why eye health remains one of our foundation’s strongest ongoing pillars. Guided by this philosophy, we have performed a total of 13,900 cataract surgeries across Tanzania, a figure that continues to grow (Mo Dewji Foundation, internal programme data, 2026).
As our programmes have expanded, operational efficiencies have allowed us to reduce the cost per cataract surgery from $123 to approximately $67, allowing us to reach more people while maximising the value of each dollar invested (Mo Dewji Foundation, 2025).
This improvement reflects how our experiences over time have continued to shape and refine how and where we deliver our eye camps.
Through our routine eye camps, we address the need for initial intervention as well as follow-up care. Additionally, we reinforce the significance of early detection through routine screenings, preventing the need for surgical intervention itself.
To bridge the gap in access, community outreach programs are essential to our approach. During our camps, we prioritize rural areas where access to services remains dire, encouraging treatment for many who are unaware of their condition, increasing uptake and bringing our services closer to them.
Within our eye program, each aspect is highly intentional; for instance, our focus on rural communities is not incidental, but reflects where our intervention can create the greatest possible impact.
Individuals in larger cities in Tanzania typically have far greater access to eye care services, but also more diversified sources of income and opportunity (Mafwiri et al., 2016; World Bank, 2024).
For someone in this position, restoring sight is indefinitely valuable, but it does not fundamentally alter the economic trajectory of their lives. In rural Tanzania, sight can be the difference between total dependency and full participation in the workforce and household economy.
An individual who regains the ability to farm, trade, or care for their family experiences not just improved well-being, but a transformative shift in their economic contribution, often for themselves and everyone who depends on them.
It is this population, the poorest and most isolated, whose recovery carries the greatest multiplier effect: the most significant gain for the individual and, in aggregate, the most meaningful contribution to Tanzania’s broader economic development.
As the Mo Dewji Foundation continues expanding eye care access across Tanzania, we hope to demonstrate that restoring sight is not simply a medical intervention, but one of the most impactful investments a country can make to its people.
As we increase scalability in hopes of nationalizing our cataract strategy, we are committed to ensuring that preventable cataract blindness becomes not only rare in Tanzania, but almost non-existent.
Nyla Mohammed Dewji is an officer at the Mo Dewji Foundation
