The Sustainable Development Goals aim to leave no one behind. We explored the hypothesis that women without a living spouse-including those who are widowed, divorced, separated, and never married-are a vulnerable group being left behind by cataract services. Using national cross-sectional blindness surveys from Nigeria (2005-2007; n = 13,591) and Sri Lanka (2012-2014; n = 5779) we categorized women and men by marital status (married/not-married) and place of residence (urban/rural) concurrently. For each of the eight subgroups we calculated cataract blindness, cataract surgical coverage (CSC), and effective cataract surgical coverage (eCSC). Not-married women, who were predominantly widows, experienced disproportionate cataract blindness-in Nigeria they were 19% of the population yet represented 56% of those with cataract blindness; in Sri Lanka they were 18% of the population and accounted for 54% of those with cataract blindness. Not-married rural women fared worst in access to services-in Nigeria their CSC of 25.2% (95% confidence interval, CI 17.8-33.8%) was far lower than the best-off subgroup (married urban men, CSC 80.0% 95% CI 56.3-94.3); in Sri Lanka they also lagged behind (CSC 68.5% 95% CI 56.6-78.9 compared to 100% in the best-off subgroup). Service quality was also comparably poor for rural not-married women-eCSC was 8.9% (95% CI 4.5-15.4) in Nigeria and 37.0% (95% CI 26.0-49.1) in Sri Lanka. Women who are not married are a vulnerable group who experience poor access to cataract services and high cataract blindness. To "leave no one behind", multi-faceted strategies are needed to address their needs.