The galactic centre can only be observed at certain wavelengths - such as X-rays - because large amounts of dust lie in our line of sight, blocking out optical light.

BBC: Arches Cluster, Leicester

Perot's eyes light up at the sight of yellow school buses in front of Houston's Museum of Natural Science.

WSJ: How Dallas Does Philanthropy: Perot Museum of Nature and Science

Medieval scholars were particularly fascinated by the science of optics and invented eye glasses partly as a result of their studies using lenses to determine the nature of light and the physics of sight.

FORBES: Connect

The sun had dropped behind the bluffs already, so that the tops of the bare trees showed up finely spiky, like hair or fur, against a yellow glow of light from somewhere out of sight.

NEWYORKER: Friendly Fire

This crisp, stunningly beautiful sight is not something we get to enjoy in light-flooded Sydney.

BBC: Meet July��s BBC Travel Photo Nomad

Imagine the heat in the summer, the bitter cold in the winter, and Mandela going out to quarry stone, the burning white light reflecting off the limestone permanently and deeply injuring his sight.

FORBES: Leadership Renewal: From Good to Great

The sight of small white figures endlessly regrouping, wandering about, pondering the light, all seen from one fixed angle, made poor spectator sport and even worse television.

ECONOMIST: Kerry Packer

This was how we spoke of the local people: they were souls, they were transient spirits, a face in the window of a passing car, runny with reflected light, or a long street with a shovel jutting from a snowbank, no one in sight.

NEWYORKER: Midnight in Dostoevsky

It may bring to light some cases in which accusations were kept under wraps and the accused were kept out of the sight of the law or accusers.

CNN: STORY HIGHLIGHTS