Blue light is a common part of the visible spectrum. In simpler words, it is a component of the light we have all around us. It is in both sunlight and the light emitted by electronic devices, such as computer screens, mobile phones, smart watches, and everything in between.

As with any other component of the light spectrum, blue light has its particular purpose. Based on the changing wavelength, blue light rays can range from very dangerous to quite useful (during the day).

Blue light rays with the shortest wavelength have the highest amount of energy and are the most harmful. However, the higher the wavelength the less dangerous the blue light. To be specific, blue light rays with wavelength of 450 nm or shorter are considered very harmful, while those between 470 nm and 500 nm are deemed healthy during the day.

The range of blue light that is healthy for our brain chemistry in daytime helps produce melatonin – a hormone that regulates the body’s sleep-wake cycle. When we take in too much blue light even during daytime often through excessive use of computer or smartphone screens, they hurt our eyes and skin. But in the night time, these harmful effects double up, disturbing the sleep-wake cycle along with more damage to the eyes.