Microscopic spheres of calcium phosphate have been linked to the development of age-related macular degeneration (AMD), a major cause of blindness. AMD affects 1 in 5 people over 75, causing their vision to slowly deteriorate, but the cause of the most common form of the disease remains a mystery. The ability to spot the disease early and reliably halt its progression would improve the lives of millions, but this is simply not possible with current knowledge and techniques.