I submitted the Economist story on this study but HN flagged it. https://www.economist.com/science-and-technology/2018/08/04/wear-glasses-earn-more https://www

I submitted the Economist story on this study but HN flagged it. https://www.economist.com/science-and-technology/2018/08/04/wear-glasses-earn-more https://www.economist.com/science-and-technology/2018/08/04/... > The first randomised control trial to measure the impact on productivity of reading glasses was carried out recently in a tea estate in Assam, in north-eastern India, paid for by Clearly, a charity. Nathan Congdon, a professor of ophthalmology at Queen’s University, Belfast, and his colleagues gave spectacles to half of a group of 751 tea-pickers aged over 40. The other half got none. Over 11 weeks, the productivity of those whose sight had been corrected rose by 39%. It rose for the others, too, showing the importance in such trials of having a control group. But that rise was only 18%. The rise in productivity for those with glasses was the largest caused by a medical intervention that has ever been shown in such a trial (others have been of mosquito nets and micronutrients). Since tea-picking is piecework, productivity translates directly into money. > Before Dr Congdon’s trial, none of the 751 had worn glasses. Given the potential gain in income, and the cheapness and simplicity of spectacles, that seems odd. It is not, however, unusual. Some 1.1bn people suffer from uncorrected long sight. In this, as in many areas of health, both governments and the market fail the poor. > Poverty is one explanation. Liberia, says Dr Congdon, has but two eye doctors, both in the capital. Even in China, which is far better-served, half of those with poor sight do not have the glasses they need. There are social issues: some people worry that spectacles make them look ugly. There are regulatory hurdles, too. In some countries, only licensed operators may sell glasses, so hardly anybody does. And because long sight creeps up on people, victims get used to it: “They probably thought, ‘you get to 50, you can’t pick like you used to’,” says Dr Congdon of the tea-pickers. “But by the end of the trial, their productivity was as good as the youngsters’.”