Children need good vision from birth until the age of seven years to ensure that their brains develop the visual pathways that will lead to healthy adult vision. Anything that obstructs their vision during this crucial time can result in lifelong visual impairment or blindness, as well as delays to their overall physical, mental, and social development; this is the case even if their eye condition is treated when they are older. The articles in this issue are designed to be as accessible as possible, so you can use them to refresh your own knowledge or adapt them for teaching.