Light sensor keeps you awake
Right behind the eyes, a light meter helps your body distinguish between night and day.
Your biological clock is really a bundle of brain cells known as the suprachiasmatic core. The brain region keeps track of night and day via nerve links to the retina of the eye, which measure the quantity of light around you. Based on the light intensity, the suprachiasmatic core reduces or increases the quantity of hormones such as melatonin and cortisol, which affect how tired you feel and how much energy your body is converting.
The biological clock can be confused, if you are affected by bright computer or smartphone light right before bedtime. According to studies, the light from the devices suppress the melatonin sleep hormone, changes the circadian rhythm, and makes us less attentive the next morning – not to mention it causes insomnia!