To avoid harm, the eye defends itself: it narrows its pupils, the eyelids close, you look away from intense light to protect the retina.
Blue light is part of the natural light spectrum but, while the sun’s blue light spectrum has a long wavelength due to distance and attenuated by the earth’s atmosphere, the same cannot be said for blue light emitted by device screens, with higher frequencies.
Blue light is not harmful in itself but excessive and prolonged exposure to it is, such as exposure on smartphone screens.
Exploited to render screens clearer under sunlight, recently, it has been widely investigated to confirm or exclude its link to early macular degeneration of the retina, damage to the lens – such as cataracts – and conjunctival and corneal inflammation.
Nobody needs advice.
We know it’s pointless to advise you against prolonged and fixed exposure to a screen, but certain behavior can easily turn into habits: look away whenever you can (every 20 minutes is advisable) towards a point in the distance to relax and rest the eyes.
This simple exercise gives are eyes a moment of respite and trains them to quickly accommodate vision at different focal points. Not to do so excessively fatigues eyesight. Screens inhibit normal blinking of the eyelids, an important function to hydrate the cornea.
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If your eyes are tired or red, see an eye specialist (don’t put it off) and consider advice to adopt lenses that reduce the quantity of blue light that reaches your eyes.
Ever been blinded by modern LED or Xenon headlights on the highway?
In the evening, and in all poor lighting conditions, the eye switches sensitivity from green to blue, that is perceived more intensely.