Close Since the light bulb was patented in 1879, mankind has been guided day and night by artificial lighting, now available from television sets to smartphone screens - and a growing body of research proves their effect on our circadian rhythm. Basically, using gadgets with screens during nighttime interfere with our ability to get that good night's sleep. While there are apps and products that supposedly help mitigate the effect of artificial lighting, the relationship between technology and the body clock is not as simple as it seems. (Photo : sik92 via Pixabay) Understanding the Human Circadian Rhythm The circadian rhythm or cycle is a natural and internal process in most living beings - a body clock if you will - that regulates the sleep-wake cycle and follows a 24-hour pattern, in line with the Earth's day and night cycle.