Energy-saving lightbulbs could be giving us all headaches as they flicker too much.
LED bulbs can bring on feelings of dizziness and pain within just 20 minutes of switching them on, an expert has warned.
Professor Arnold Wilkins, professor of psychology at the University of Essex, said the flickering of the unpopular lights is stronger than for traditional lightbulbs.
While fluorescent lights, such as those in offices, dim by around 35 per cent with every flicker, LED lights dim by 100 per cent. It means they effectively turn off and on again hundreds of times every second.