The international accord on Iran's nuclear programme agreed this month in Switzerland offers no timeline for lifting international economic sanctions, which profoundly affect public health (see, for example, S. Shahabi et al. Nature 520, 157; 2015). This must be urgently rectified because, as the Iranian health minister has stressed, it will take a year to restore public-health systems after sanctions are lifted.

By driving up prices and limiting the availability of medicines, sanctions are forcing people and clinics to use poor-quality, black-market medications. A shocking example still under investigation is last month's unexpected permanent loss of vision in 15 people after eye surgery in a Tehran clinic, with unknown numbers similarly affected at two other centres. The tragedy is thought to have arisen from a non-standard ampoule (see go.nature.com/oyudtj; in Persian).

Health care is a fundamental human right (see go.nature.com/xqtarv and go.nature.com/xuoeyb). Specialists in human rights, such as the United Nations special rapporteur on human rights in Iran, Ahmed Shaheed, should remind the US Congress and other Western governments of the importance of lifting sanctions and of a clear strategy to rapidly improve the country's public health.