Why humans see clearly

A transparent cornea is essential for vision, which is why the eye has evolved to nourish the cornea without blood vessels. But for millions of people around the world, diseases of the eye or trauma spur the growth of blood vessels and can …

Words help people form mathematical concepts

Language may play an important role in learning the meanings of numbers, scholars at the University of Chicago report.
A study based on research on deaf people in Nicaragua who never learned formal sign language showed that people who communicate …