Energy-saving bulbs 'get dimmer'

Energy-efficient light bulbs lose on average 22% of their brightness over their lifetime, a study has found.

In some cases they emit just 60% as much light as traditional models which are being phased out of shops, it says.

The study in Engineering and Technology magazine concluded that consumers were being misled by the bulbs’ packaging.

Of the 18 energy-saving bulbs tested over 10,000 hours by the Institution of Engineering and Technology, three stopped altogether.