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What are the long-term effects of blue light exposure and are you getting too much of it?

Exposure to blue light can have lasting effects on our healthy, including our sleep as it alters our circadian rhythm.

By Bio Island Nutrition Team

Over the recent years there has been a lot of attention drawn to blue light and our eye health. So, what is blue light and is it really effecting our eyes?

Blue light is the shortest wavelength in the visible spectrum, it makes up approximately one third of all visible light. Our main sources of blue light include sunlight, however, there are a number of man-made sources of blue lights. This includes fluorescent and LED lighting, and display screens such as tv, tablets, computers, and mobiles. With the rise of technology become more and more common in the household and spending multiple hours in front of a screen this has increased the exposure of blue light and has led to an increase in sleep disturbances and eye health issues.

This high energy blue light passes through the cornea and lens to the retina causing diseases such as dry eye, cataract, age related macular degeneration, even stimulating the brain, inhibiting melatonin secretion and enhancing adrenocortical hormone production, which alters hormonal balance and directly affects sleep quality (1). 

The retina is the initial site of vision formation, and it is also the main spot of various blinding eye diseases. Blue light’s wavelength focus in front of the retina so after a long period of time blue light can cause visual fatigue and near-sighted tiredness which can lead to an inability to concentrate and deplete people’s ability to learn and working efficiency (1). As the retina plays an important role in preventing blindness constant penetration of blue lights may contribute to some eye diseases.

Exposure to blue light can have lasting effects on our sleep as it alters our circadian rhythm and suppresses production of melatonin (2). The pineal gland in the brain is supposed to release melatonin a couple hours before bedtime and melatonin reaches its peak in the middle of the night, however blue light wavelengths can suppress this product of melatonin in the evening, leading to a longer period of time to fall asleep, plus this decreases the REM sleep cycle and wake up feeling sleepier then ever. Even if we are asleep for 8 hours.

The suppression of melatonin can then also have a back lash on our circadian rhythm. Our circadian rhythm uses light to keep our bodies in sync with day and night. So, when the sun rises our bodies know it is time to wake up and when the sun goes down it knows to go to bed. This withdrawal of light lets us prepare for a perfect night’s rest with a release of melatonin. Due to this suppression of melatonin and still looking at lights even when the sun is away you can image in puts our circadian rhythm out of whack causing a jet lag effect.

So finding ways to best reduce the exposure to blue lights will lead to a perfect nights sleep and keeping out eyes working at their best.

Ways to reduce the impact of blue light is by:

  • Reducing exposure to bright and blue lights in the evening, at least two hours before bed.
  • Turn off close range electronic devices at least one hour before.
  • Keep all electronics out of the bedroom.
  • Get exposure to sunlight in the morning.
  • Opt for dim red lights in the bedrooms and bathrooms.
  • Apps can be downloaded that remove that dim blue light on mobiles, tablets and laptops.
  • Blue light glasses can also be purchased which block the blue light wavelengths.



  1. Zhao, Z. C., Zhou, Y., Tan, G., & Li, J. (2018). Research progress about the effect and prevention of blue light on eyes. International journal of ophthalmology, 11(12), 1999–2003. doi:10.18240/ijo.2018.12.20
  2. Tosini, G., Ferguson, I., & Tsubota, K. (2016). Effects of blue light on the circadian system and eye physiology. Molecular vision, 22, 61–72.

This information does not take into account your personal situation and is general in nature. You should consider whether the information is appropriate for your needs and seek professional medical advice.

Always consult your healthcare professional before taking any supplements or if any concerns arise.