Blue Light And Its Impact On Vision

What Is Blue Light?

Blue light is a colour in the visible light spectrum with a wavelength typically ranging from approximately 400 to 495 nanometres. Within the visual spectrum, blue light is located between violet and green. It has one of the shortest wavelengths and highest energy levels among visible light colours.

Blue light, like other colours of visible light, is all around you. The sun emits blue light. So do fluorescent and incandescent light bulbs. Human beings are exposed to more blue light than ever because of the widespread use of devices that rely on light-emitting diode (LED) technology.

Computer and laptop screens, flat-screen televisions, cell phones, and tablets all use LED technologies with high amounts of blue light.

Advantages Of Blue Light

Blue light offers a number of advantages that are useful to our well-being. Some of these include:

1. Regulation of Circadian Rhythm: Blue light plays a crucial role in regulating our body's natural sleep-wake cycle. Exposure to blue light during the day boosts alertness, helps maintain cognitive function, and improves mood by increasing the production of serotonin. This is particularly important for setting our internal clock, or circadian rhythm.
2. Vision and Cognitive Performance: Blue light enhances contrast and colour perception, which can improve visual acuity and make reading tasks easier, particularly in low light conditions. It helps in alerting the brain to wakefulness and can therefore enhance performance on tasks requiring attention and cognition.
3. Skin Treatment: Some studies have shown that blue light kills acne-causing bacteria and lowers inflammation in acne breakouts. Research has also revealed that blue light therapy is effective in treating basal cell carcinoma tumours.
4. Mood Enhancement: Blue light can help elevate mood, which is why bright light therapy is used to treat conditions like seasonal affective disorder (SAD).

Negative Effects Of Blue Light

Blue light exposure from screens is small compared to the amount of exposure from the sun. However, there is concern about the long-term effects of screen exposure from digital devices. This is especially true when it comes to spending too much time on screens, and having screens too close to the eyes.

Since our eyes are not good at blocking blue light, nearly all visible blue light passes through the cornea and lens. It then reaches the retina, where the brain processes it into images.

While blue light is good for regulating our circadian rhythm and mood, excessive exposure to artificial sources of blue light, such as digital screens and LED lighting, has become a cause for worry.

Here are some adverse effects of blue light on vision:

1. Digital Eye Strain: Prolonged exposure to screens emitting blue light, such as computers, smartphones, and tablets, can lead to digital eye strain. Symptoms include dry eyes, blurred vision, headaches, and neck or back pain. This is partly because blue light scatters more easily than other visible light, causing glare and reducing contrast.
2. Sleep Disruption: Excessive blue light exposure, especially in the evening or night, can suppress the production of melatonin, the hormone responsible for sleep. This disruption can lead to difficulty falling asleep, poor sleep quality, and potential long-term health issues like increased risk of obesity, diabetes, and cardiovascular disease.
3. Potential Retinal Damage: High-intensity or prolonged exposure to blue light might contribute to photoreceptor damage, or contribute to the development and progression of age-related macular degeneration (AMD).
4. Blue Light Hazard: The term "blue light hazard" refers to the potential for blue light to cause photochemical damage to the retina. This is more of a concern with high-energy, short-wavelength blue light, which is less filtered by the eye's natural lens.

Management And Prevention

Excessive exposure to blue light, particularly from digital devices, can lead to eye strain, disrupted sleep cycles, and potential long-term effects on eye health. To mitigate these risks, effective management and preventive strategies are essential.

You are probably reading this from a device that emits blue light, so you cannot avoid it altogether. However, you can take several measures to protect your eyes, including:

1. Blue Light Filters: Many devices now offer built-in settings to reduce blue light emission, like "night shift" on iPhones or "blue light filter" on Android devices. Blue light filtering glasses are also available for those spending long hours in front of screens.
2. Screen Time Management: Limiting screen time, especially before bedtime, can help mitigate the impact on sleep. Using dim red lights for night-time activities can be less disruptive to melatonin production.
3. Regular Eye Breaks: Adhere to the 20-20-20 rule: every 20 minutes, look at something 20 feet away for at least 20 seconds. This helps reduce eye strain.
4. Environment: Adjusting screen brightness to match the lighting in the room, reducing glare, and ensuring proper lighting can also help.
5. Eye Moistening: Eye drops (such as artificial tears) and room humidifiers are all good ways to keep your eyes from becoming too dry and irritated while you’re using blue-light-emitting devices.
6. Warm Lighting: In your home environment, use warm, amber-toned lighting, especially in the evening, to reduce overall blue light exposure.
7. Diet and Lifestyle: A diet rich in antioxidants (like lutein and zeaxanthin found in leafy greens) might offer some protection to the eyes against blue light damage.

If you have any questions regarding eye care at Optimax, please don’t hesitate to get in touch with us. We are more than happy to discuss queries with you over the phone (0800 093 1110) or email (enquiry@optimax.co.uk).