What is blue light and why should I care?
UV light causes damage to the anterior part of the eye, most notably the crystalline lens, a process leading to cataract formation. Blue light, however, can affect the circadian rhythm (sleep-wake cycle) or the macula depending on the wavelength of blue light that reaches the retina. When harmful blue light penetrates the eye, it causes accelerated retinal cell damage leading to early development of age-related macular degeneration (AMD).
What are the sources of blue light?
Much like UV light, blue light is present everywhere. Since blue-violet is part of the visible light spectrum, it is present indoors and outdoors. The amount of exposure to blue light outdoors varies depending on time of the day, location, season, etc. Sunlight emits blue light all year long regardless of the season. The average proportion of blue light emitted from the sun during the day ranges between 25-30%.
Over the past several years, there has been an increase in the use of LED light indoors. LED bulbs are energy efficient and last up to 10 times longer than the incandescent bulb. It is due to this long lasting quality that LED bulbs act as the light source for most digital devices including but not limited to: computers, tablets, and most smart phones. This is a health-related concern, as LED lights contain up to 35% of harmful blue light.
Harmful Versus Beneficial Light
Not all blue light causes damage to your eyes. Blue light can be divided into two categories: beneficial and harmful. We will discuss the differences between each type of blue light and the roles they play on your body and health below.
- Blue-Turquoise light (465nm-495nm) plays an essential role in regulating the circadian rhythm (sleep/wake cycle), memory, cognitive performance, and other contributing factors to general wellness.
- The rest of the visible light spectrum (green, yellow, orange, and red) is essential for color perception & acuity
- UV light damages the front of the eyes (i.e. the crystalline lens and cornea) and is a major risk factor for the development of many eye diseases, including but not limited to cataracts.
- Blue-Violet light (415nm-455nm) is a high-energy visible (HEV) light that after years of exposure may cause long term damage to retinal cells. A study conducted between Essilor & the Paris Vision Institute has suggested that blue-violet light may be a risk factor for the onset of age-related macular degeneration (AMD), the leading cause of blindness in adults over 60.*
- The result of a comprehensive study between Essilor & Paris Vision Institute revealed that 40nm (415-455nm) of the HEV spectrum – known as Blue-Violet light – may be the most harmful.
- *We will learn more about the full extent of potential retina damage with time and further research.
*HEV=High Energy Visible Light *UV=Ultra-Violet
Blocking blue-violet light from digital devices has become increasingly important as children and adults alike spend more and more time on tablets, televisions, smart phones, and computers.
Children’s eyes are under-developed and their eye structures are more transparent so they have little natural protection against harmful light.
Your eye defense system weakens with age and causes the ocular structures, like the macula, become more fragile; therefore, those at risk for development of eye disease like Age-Related Macular Degeneration (ARMD) must be protected from harmful blue light.
There are a couple of methods you can employ to help protect your eyes from blue-violet light:
- Flux is a free software you can download onto your computer that changes the coloring of your display to adapt to the time of day. You will notice the most difference at night as your computer screen becomes filled with warmer tones.
- Apple Night Shift is similar to Flux but for your iPhone and iPad.
- Premium blue light protection anti-reflective coating for your glasses. There are many types of anti-reflective coatings that claim to block out harmful light, but how do you know if it is a good coating or not? See our list below for important qualities of a blue light protection coating.
- Vision-specific medical food, like Lumega-Z, that designed specifically to restore and maintain a robust macular pigment may be an important addition to your diet.
Essential Properties of a Premium Blue Light Protection Coating
- Filters out harmful UV and Blue-Violet light to improve contrast and alleviate eye fatigue; allows beneficial Blue-Turquoise light through for circadian rhythm regulation
- Allows for good color perception and vision while keeping the lens transparent
- Eliminates glare, scratches, smudges, dust and water
Available Premium Blue Light Protection Coatings Today:
- Essilor Prevencia / Types of Crizal Coatings / The Science Behind Prevencia
- HOYA Recharge™
- BluTech Lenses
- Zeiss DuraVision® BlueProtect
- Blue Light Eye Protection
For more information about the damaging effects of harmful blue light:
Dr. Shen Lee – The Benefits and Dangers of Blue Light
Vision Monday: Blue Light Research Compendium
Blue Light Hazard: New Knowledge, New Approaches to Maintaining Ocular Health
The Benefits and Danger of Blue Light for your Eyes
The Benefits and Dangers of BLUE LIGHT
iPad Insomnia: Light from electronic screens at night linked to sleep loss
Blue Light has a Dark Side
Exposure and Use of Mobile Media Devices by Young Children
Can kids’ devices be ruining their eyes?