Blue light is a type of high-energy visible (HEV) light that is emitted by electronic devices such as smartphones, tablets, laptops, and televisions. It has a short wavelength and high frequency that makes it appear blue.

Blue light is beneficial during the day, as it helps regulate our circadian rhythms and improve alertness and mood. However, exposure to blue light at night can be problematic. The blue light emitted by electronic devices interferes with our sleep-wake cycle by suppressing the production of melatonin, a hormone that regulates sleep. This can make it difficult to fall asleep and get enough rest, leading to symptoms such as fatigue, irritability, and decreased cognitive performance.

To reduce the impact of blue light on sleep, experts recommend using blue light filtering technologies such as blue light blocking glasses, software applications that reduce the amount of blue light emitted by devices, or avoiding screens for several hours before bedtime.