There are 2 kinds of blue light : natural blue light emitted by the sun and artificial blue light emitted by LEDs (Visible Light Energy).
Solar blue light is one of the elements of the light spectrum; it is the light composed of UV and blue located at the border of the visible and the UV. This is not very harmful for a healthy eye and for wavelengths close to yellow even beneficial for our health.
On the other hand, artificial blue light is dangerous for the eye . We are all more and more confronted with it with technological development; this is the light emitted by a large number of everyday devices: PCs, flat screens, smartphones, tablets, tom-toms… and also by public and domestic lighting. Indeed, for economic and durability reasons, LEDs are replacing incandescent and halogen bulbs, etc.
All of these modern light sources emit a high proportion of blue light radiation called HEV (High Energy Visible).
Many studies have shown that even low sustained but repeated exposure is harmful; it is the cause of various visual disorders or genes such as tingling eyes, headaches and can also cause damage to the ocular annexes (lens, retina, eyelid, etc.) such as premature cataracts, AMD, etc.
The impacts of this light on humans are multiple because daily exposure to these devices not only damages our sight but also affects our circadian rhythm, that is to say our biological clock . These wavelengths of light stimulate the hormones of awakening and looking at your iPad, tablet or console at night can prevent you from falling asleep even when you are tired .
On the other hand, the strong stroboscopic effect (the large fluctuations in visually imperceptible light intensity) is the cause of glare .
The negative effects of LEDs are greater in children, the elderly, people undergoing photosensitizing medical treatment, aphakic people, etc.
This is why it is recommended to limit exposure to these light sources, especially among people most at risk and in the evening, then to protect yourself with specific anti-blue light glasses which protect your eyes from this radiation by absorbing a part of blue light .