How Blue-light is harmful and where is it from?

Our eyes detect a narrow band of wavelengths referred to as the “visible light spectrum”, which consist of the three primary colours: Blue (380–490nm), Green (490–590nm), and Red (590–780nm). These wavelengths transmit through to Retina, a light-sensitive layer of tissue lining the inner surface of the eye, and are ultimately sent various visual centres of the brain.As mentioned, blue-light (380–490nm) is being shorter in wavelength, thus carries more energy compare to other visible light. If light is allowed to reach retina directly without any protection mechanism, blue-light can inflict more damage on retina than the other colour.

Research has determined that the lens inside our eye is able to filter out Red and Green light as they carry less energy. However, it is not able to filter out the high energy blue light. Adolescence and prepubescence are more vulnerable to such damage than matured adults, which permits more light to impact on the sensitive retina.

Light from electronic devices is the light source we are most exposed to in our daily activities, only second to light from natural sources. Because of the wide spread and heavy use of electronic devices nowadays, such as monitor, TV screen, tablet and smart phone, it has drastically increased our exposure to the dangerous blue-light.