Scientists have cracked a problem that popular opinion suggests they suffer from most: steamed-up spectacles.
The solution, they found, lies in nanotechnology, the science of the vanishingly small. By applying an ultra-thin coating of particles to sheets of glass and other transparent surfaces, scientists at Massachusetts Institute of Technology made them permanently fog-proof.
Glasses steam up and car windscreens fog over when they are cold and meet warm, moist air, making thousands of tiny droplets of water condense on to the surface. The droplets scatter light as it passes through them, producing the misty, blurred effect.
The coating, a thin sandwich of transparent plastic and layers of silica particles too small to be seen with the naked eye, works by attracting water more strongly than the glass does. This flattens each of the water droplets, smearing them over the surface in a see-through layer.