Myopia, or nearsightedness, is affecting people at record levels across the globe. Around half of the population in America and Europe has the condition, which is double the percentage from 50 years ago. East Asia in particular seems to be suffering from the "myopia boom": up to 90% of Chinese teenagers are shortsighted, and 96.5% of 19-year-old men in Singapore are, too. Scientists have predicted that half of the world population, or about 5 billion people, will have myopia by 2050. This is a real health concern, because some of those people will have high myopia, a condition that can lead to detached retinas, glaucoma, and blindness.