Nigeria, Oct. 6 -- In 1851, Hermann von Helmholtz devised the ophthalmoscope, allowing doctors to look at the back of a living eye and see its tiny blood vessels. Today, someone who comes to an eye clinic because reading has become difficult may leave with a prescription for spectacles. The examination can also reveal an eye disease or changes that call for a check for diabetes or high blood pressure. Either way, the person needs to understand what was found and what to do next.

The Eye and the Rest of the Body

Researchers studying eye scans and health records from two large groups in Britain recently found that people with a thinner layer of nerve cells at the back of the eye were more likely to be diagnosed later with atrial fibrillat...