Your smartphone or tablet computer could be causing you to sleep badly.
New research published in the Journal of Nature has found that artificial lights on gadgets can play a key role in causing users to sleep badly by disrupting the natural rhythm of the body.
The lights can have an effect on chemicals in the brain and drive people to use stimulants like caffeine to stay awake longer.
The research also shows that the decline in the number of hours people sleep can affect public health, leading to obesity, depression and heart disease.
