Health experts in the UK have warned that energy-saving light bulbs could lead to migraines.
The Migraine Action Association (MAA) has explained how these bulbs have caused attacks of the powerful headaches amongst some of its members.
Several bulbs use a technology similar to fluorescent strip lights, and some migraine sufferers say they produce a flickering effect that triggers their condition.
Low energy light bulbs use only a quarter of the energy consumed by traditional versions.
Within next four years, the British government will phase out traditional bulbs in a bid to reduce carbon dioxide emissions.
In September, Environment Secretary Hilary Benn said that a voluntary agreement with retailers would remove all conventional bulbs from the shops by December 2011.
However, Karen Manning, from MAA said that doing so could harm some sufferers.
"These bulbs do trigger migraines for some of our members - it's either the flickering, or the low intensity of the light, causing eye strain," BBC quoted Manning, as saying.
"We would ask the government to avoid banning them completely, and still leave some opportunity for conventional bulbs to be purchased," she added.
However, the Lighting Association, which represents bulb manufacturers, denied that modern designs produced a flicker.
"A small number of cases have been reported by people who suffer from reactions to certain types of linear fluorescent lamps. These were almost certainly triggered by old technology," a spokesman said.
In 2006, the charity Epilepsy Action revealed that a small number of people with the illness could have seizures caused by low-energy bulbs.