Why does blue light affect our sleep?
Because there is a kind of photoreceptor cells in the retina of the eye, called "retinal specialized photoreceptor ganglion cells" (ipRGCs). It contains a newly discovered photoreceptor protein called substantia nigra, which produces a series of chemical reactions to light, causing ipRGC cells to discharge under light. This cell does not form vision, but is directly transmitted to the suprachiasmatic nucleus (SCN) of the hypothalamus through the optic nerve and participates in mediating the circadian rhythm. This photoreceptor is connected to the biological clock in the human brain. The light it receives inhibits the secretion of melatonin from the pineal gland. Melatonin is also called the "sleeping hormone". When the amount of melatonin in the human body reaches a certain level, People will feel tired and drowsy.
The main thing that affects people's sleep is a hormone called melatonin, which plays an important role in adjusting the body's circadian rhythm.
When we read a book or play with a mobile phone at night, the blue light of the book lamp and mobile phone will irradiate our eyes, thereby stimulating the ipRGC cells in our retina, causing it to inhibit the secretion of melatonin by the pineal gland, so that the concentration of melatonin can reach Less than the amount to fall asleep makes us excited and unable to fall asleep, thus affecting our sleep.