If you want a good night's sleep, switch off the TV, computer and mobile phone an hour before going to bed, experts say. Nine in ten people admit using electronics in the hour before turning out the lights – and it's wrecking¹ their sleep patterns, it is claimed。

Artificial light emitted by TV and computer screens and over-stimulation of the brain has been blamed. The worst activities are video games, using mobiles and surfing the internet, according to a survey by the US National Sleep Foundation。

Charles Czeisler of Harvard Medical School said: "Artificial light exposure between dusk and the time we go to bed suppresses release of the sleep-promoting hormone² melatonin enhances alertness and shifts normal sleep patterns to a later hour."

Even after lights out technology is disrupting sleep. One in ten people in their 20s said they were routinely woken during the night by a phone call, text message or email。

专家建议：如果你想一夜好眠，那么就在上床1个小时之前关掉电视、电脑以及手机吧。据了解，9成受访者表示在关灯睡觉前使用电器产品，而这一习惯破坏了人们的睡眠模式。

电视和电脑屏幕散发出的人工光线对大脑的过度刺激饱受诟病。而据美国睡眠基金会的一项调查显示，后果更为严重的则是电子游戏、使用手机以及上网冲浪等活动。

哈佛大学医学院教授查尔斯称：“睡前置身于人工光线会抑制褪黑激素的释放(该激素可催眠)，提升兴奋度，并将正常的睡眠模式推迟到较晚的时间。”

而即使在关了灯的情况下，人们的睡眠还是会受到干扰。9成20多岁的受访者反应，他们经常在半夜被电话、短信或电子邮件提示声吵醒。