Across low-and-middle-income countries, less than half of 10-year-old children can read. This alarming phenomenon has been labelled by education experts around the world as the global ‘learning crisis’: A bitter-sweet situation in which we have achieved near universal primary education, including gender parity, but in which children are not achieving sufficient mastery of basic literacy and numeracy.

Policymakers will need to use a variety of tools to address the learning deficit. One promising but under-considered intervention is hiding in plain sight: eyeglasses.