Unveiling the Impact of Blue Light on Ocular Health

Shaila Shakil, B. Optom

Student, NSHM Knowledge Campus – Kolkata, India

In an era dominated by digital screens, our eyes are constantly exposed to the screens emitting blue light from smartphones to computers, tablets to LED lighting, etc. This exposure to blue light has become ubiquitous. Blue light is a type of visible light with wavelength between 400 to 495 nm. ⁽¹⁾ It is characterised by its shorter wavelength and high energy compared to other colours in the visible light spectrum.

The human eye is structured to block UV rays from reaching the retina, however, it is not as effective in blocking out blue light, which almost passes through the cornea and lens, reaching the retina. ⁽¹⁾

Sources of blue light

• The Sun: The sun is the primary natural source of blue light. It’s the reason why the sky appears blue during the day. As we know sunlight is also important for the growth and development of eyes and vision in children but perceiving it for a longer time can have harmful effects . ⁽²⁾
• Artificial resources: Artificial sources of blue light include fluorescent light, LED TVs, computer screens, smartphones, and tablet screens. ⁽³⁾

While the blue light plays a natural role in boosting alertness, improving memory during the day, it is also harmful. Excessive exposure can lead to harmful effects on the health such as

• Digital eye strain: Blue light has high frequency and scatters more easily that is why constant exposure of blue light through digital screens can lead to eye strain, fatigue, dryness , redness, and peppering sensation. ⁽³⁾
• Impact on retinal cells: Research suggests that prolonged exposure to blue light can have adverse effects on retinal cells. It also contributes to the development of age-related macular degeneration (ARMD) which is the leading cause of vision loss in adults. ⁽⁴⁾
• Sleep Disruption: Blue light suppresses the production of melatonin (a hormone which regulates our sleep and wake up cycle). Excessive exposure of blue light before bed can disturb the natural sleep signal and can lead to the issues of vertigo.  ⁽⁴⁾
• Disruption of Circadian Rhythm: The body’s internal clock relies on the balance between the exposure to natural daylight during the day and the darkness at night. Artificial blue light exposure can confuse this system leading to irregular sleep patterns and health consequences. ⁽⁴⁾

Ways to protect eye health from blue light:

As an eye care professional, we can counsel our patients regarding blue light exposure and its harmful effects and ask them to follow some simple ways to protect their eyes as mentioned below:

• Use blue light filters for your digital screens. ⁽⁵⁾
• Follow the 20-20-20 rule to reduce the digital eye strain. ⁽⁵⁾
• Limit screen time before bed. ⁽⁶⁾
• Use proper lighting and adjust display settings. ⁽⁶⁾

The impact of blue light is an area of active research. Adopting healthy screen habits and staying updated about the emerging research can help us strike a balance between our digital lifestyle and an optimal eye health.

References:

1. Pefkaros, N. (2023b, October 23). The effect of blue light on our eyes – Space Coast Ophthalmology. Space Coast Ophthalmology. https://spacecoastophthalmology.com/the-effect-of-blue-light-on-our-eyes/. [Last accessed – 13^th July 2024; 02:00pm AEST]
2. U.S. Department of Health and Human Services. . 8 things you can do right now to Protect your vision. National Eye Institute. https://www.nei.nih.gov/learn-about-eye-health/healthy-vision/8-things-you-can-do-right-now-protect-your-vision [Last accessed – 13^th July 2024; 02:10pm AEST]
3. WebMD. (n.d.-a). How does blue light affect you?. https://www.webmd.com/eye-health/blue-light-health [Last accessed – 13^th July 2024; 02:09pm AEST]
4. Stanborough, R. J. (2023, April 24). The truth about blue light and Eye Health. Healthline. https://www.healthline.com/health/what-is-blue-light [Last accessed – 13^th July 2024; 02:19pm AEST]
5. Russ. (2022, May 17). Protecting Your Eyes from Blue Light – Optometrists.org. Optometrists.org. https://www.optometrists.org/protecting-your-eyes-from-blue-light/ [Last accessed – 13^th July 2024; 02:15pm AEST]
6. The Eye Care Group. (2021, March 11). How to protect against blue light and digital eye fatigue. The Eyecare Group. https://www.eyecaregroupnc.com/how-to-protect-against-blue-light-and-digital-eye-fatigue/ [Last accessed – 13^th July 2024; 02:05pm AEST]