Shades that change colour

Chemists at the Univercity of Washington have released a demo of a prototype pair of sunglasses that have lenses that can change colour. The lenses are adjustable by the wearer, who can change the colour of the shades by turning a small button on the side of the shades arms. The technology will be applied to shades where wearers may want to have shades for different conditions - such as skiers or riders of bikes and motorcycles. Traditional shades that react to the light to darken the lenses in bright conditions do not work when shielded from UV rays (which trigger the reaction), where as these user controlled shades would work in all conditions.

Thanks to Kimm for this link.
Read more here.