Blue light is a wavelength of light emitted from the sun, and from artificial lighting & devices.
Exposure to blue light from the sun during the day is good for us, helping us to stay alert, perform well and stay in a good mood.
Overexposure to blue light from artificial sources such as monitors, tv screens, LED lighting and smartphones may cause digital eyestrain. Side effects associated with this include blurred vision, sore & tired eyes, headaches and poor quality sleep.