睡前刷手机为什么特别影响入睡?蓝光到底做了什么?
Why does late-night screen time hurt sleep so much — what does blue light actually do?
视网膜上有一种对约480纳米蓝光格外敏感的感光细胞(含黑视蛋白),它们不负责成像,却直连视交叉上核,向大脑报告「现在还是白天」。夜间长时间接收这类蓝光会抑制褪黑素的分泌、推迟昼夜钟的相位,让人该困的时候不困;实验显示睡前使用发光屏幕的人褪黑素分泌起点显著推迟,次日早晨也更困倦。暖色暗光、夜间模式或提前一小时放下手机,都是在给生物钟留出日落缓冲。
A class of retinal cells containing melanopsin is exquisitely sensitive to blue light near 480 nm. They do not form images; they wire straight to the suprachiasmatic nucleus and tell the brain it is still daytime. Sustained evening exposure suppresses melatonin and delays the circadian phase, so you feel sleepy later than you should; experiments show evening screen use markedly delays melatonin rise and leaves people groggier next morning. Warm dim light, night modes, or putting the phone away an hour earlier all give the clock its sunset buffer.
来源 · Source
Chang, Aeschbach, Duffy, Czeisler,《Evening use of light-emitting eReaders negatively affects sleep, circadian timing, and next-morning alertness》,Proceedings of the National Academy of Sciences,2015 (DOI: 10.1073/pnas.1418490112)
Chang, Aeschbach, Duffy, Czeisler, 'Evening use of light-emitting eReaders negatively affects sleep, circadian timing, and next-morning alertness', Proceedings of the National Academy of Sciences, 2015, DOI: 10.1073/pnas.1418490112
独立核验依据 · Independent verification: 核验依据 1 Crossref DOI 10.1073/pnas.1418490112