What is HEVL?

In the visible light spectrum, there is a portion of light categorized as high-energy visible light (HEVL).  HEVL  is blue-violet to blue in color, with wavelengths within the range of 400–500 nm. Often referred to as "blue light", these waves pass through the lens and reach the retina. Light in the 400–430 nm part of the spectrum is known to be particularly harmful.

High Energy Visible Light




Blue Light is Everywhere
Blue Light makes the sky blue
The eye is not very good at blocking blue light.
Blue light exposure increases the risk of macular degeneration.
Blue light contributes to digital eye strain.
Blue light protection may be even more important after cataract surgery.
Not all blue light is bad.
HPO is dedicated to protecting you from harmful blue light through innovation.


Sunlight contains red, orange, yellow, green and blue light rays and many shades of each of these colors, depending on the energy and wavelength of the individual rays (also called electromagnetic radiation). Combined, this spectrum of colored light rays creates what we call "white light" or sunlight. So how does blue light come into the equation?


There is an inverse relationship between the wavelength of light rays and the amount of energy they contain. Light rays that have relatively long wavelengths contain less energy, and those with short wavelengths have more energy. Light rays on the red end of the visible light spectrum have longer wavelengths and less energy. Light rays on the blue end of the visible light spectrum have short wavelengths and contain more energy and are considerably more damaging to the human body - skin, eyes and even our circadian rhythms which directly affect our wake-sleep cycles.






Artificial Light



Mobile Phones

The largest source of blue light is sunlight. Additionally, there are many other sources:


• Fluorescent light

• CFL (compact fluorescent light) bulbs

• LED light

• Flat screen LED televisions

• Computer monitors, smart phones, and tablet screens


The blue light exposure you receive from screens is small compared to the amount of exposure from the sun.  Nevertheless, there is concern over long-term effects of screen exposure because of the close proximity of the screens and the length of time spent looking at them. According to a recent NEI-funded* study, children’s eyes absorb more blue light from digital device screens than adults.


When you stare at a screen for hours at a time, whether it is a computer, TV, phone or tablet, you are exposed to blue light from the device. The discomfort some people have after looking at screens is most likely digital eyestrain. Most of us blink less when looking at screens, causing eye strain and dry eye.


Blue light also affects the body’s circadian rhythm, our natural wake and sleep cycle. During the day, blue light wakes us up and stimulates us. But too much blue light exposure late at night from your phone, tablet or computer can make it harder to get to sleep.


* National Eye Institute





Most of us spend the majority of our waking hours staring at a digital screen. Blue light has been known to affect our eyes.



Age Related Macular Degeneration (AMD) blinds millions around the globe. In the United States alone AMD accounts for 54% of blindness in individuals 40 years and older. Medical science has demonstrated a link between exposure to visible light primarily in the HEVL (blue/violet) region (within 400-450nm) as a causative factor in human retinal photoreceptor cell death. This cell death (apoptosis) represents one of the earliest phases of AMD. The correlation between HEVL exposure, which comes from sunlight as well as from indoor artificial light, and AMD is now well understood.  A growing number of studies and numerous papers support this link. Reducing light in the 400-450 nm range will also lead to improved contrast sensitivity.


Until now, the only known method to block these damaging wavelengths of light was with deep amber or yellow tinted spectacle lenses, blue blocking sunglasses or certain intraocular lenses (IOLs) that are usually implanted later in life after one’s retina may be predisposed for macular degeneration. High Performance Optics' proprietary technology helps preserve macular integrity by blocking these harmful light rays using a mostly colorless, highly proprietary filter technology. It is important to understand that you are also at risk indoors under artificial light.

Ranks 3rd among visual impairments


196 million impacted by 2020


Increasing to 288 million in 2040





Not all blue light is bad. Blue light between 450-500nm is considered good blue light and needed for good health. It boosts alertness, helps memory and cognitive function and elevates mood. It regulates circadian rhythm – the body's natural wake and sleep cycle. Exposure to blue light during daytime hours helps maintain a healthful circadian rhythm. Too much exposure to blue light late at night (through smart phones, tablets, and computers) can disturb the wake and sleep cycle, leading to problems sleeping and daytime tiredness. Not enough exposure to sunlight in children could affect the growth and development of the eyes and vision. Early studies show a deficiency in blue light exposure could contribute to the recent increase in myopia/nearsightedness.


The non-visual functions in humans caused by the Good Blue light depend on a newly discovered third photoreceptor(ipRGCs) containing melanopsin, which form a photoreceptive network across the inner retina. Because melanopsin is so important to the to the daily resetting of our biological clocks, its absorption spectrum is also called the chronobiological spectral band. This band is within the blue range with a peak at approximately 480 nm




The fact that blue light is both beneficial and toxic raises a critical question:  Can we protect the eye from harmful blue light without simultaneously denying the physiologically necessary good blue light?


 Filtering out ALL blue light  is NOT a healthy solution.



How does it affect our skin?

A better solution is an advanced filtering technology that selectively filters out the harmful wavelengths while transmitting the beneficial ones. This requires advanced research and technology design that will filter out bad blue light while also allowing the important good blue light to pass to our eyes. HPO introduced selective filtering to the world. This is what separates our technology from any other Blue Filtering. In addition, HPO has partnered with advanced chemistry development partners to invent new chemistry that allows for the production of such selective filters which can be integrated to a host of commercial applications that can shield the retina and skin from harmful HEVL while allowing good blue light to pass through the application.  <LEARN MORE>




Increasing consumer awareness regarding the dangers of excessive UVA and UVB exposure has worked in the industry's favor by boosting demand for sun-protection products. Sun-protection products continue to be increasingly popular with consumers.


Globally, sun protection products represent the largest segment in the sun care products market. Rising concerns about exposure to ultraviolet radiation and the need to prevent skin damage are contributing to the increased demand for sun protection products with requisite SPF levels. The market for after-sun products is driven by the growing demand for products with skin care, anti-aging and relaxation properties.


The future looks bright for the Sunscreen Manufacturing industry. The industry's performance over the next five years will be underpinned by growing per capita disposable income and heightened demand from drugstores.




A persistent misconception is that visible light is safe for the skin. In reality, visible light can damage melanocytes through melanin photosensitization and singlet oxygen (O2) generation, thus decreasing cell viability, increasing membrane permeability, and causing both DNA photo-oxidation and necro-apoptotic cell death.


Although melanin can protect against cellular damage induced by UVB, exposure to visible light leads to pre-mutagenic DNA lesions (i.e., Fpg- and Endo III- sensitive modifications); these DNA lesions may be mutagenic and may cause photoaging, as well as other health problems, such as skin cancer.


When the cells were pigmented and treated with 36 or 72 J.cm2 of visible light, both cell lines exhibited substantial decreases in viability (50% for H36, 25% for M36 and 40% for M72), which clearly demonstrates that the presence of melanin increases visible light.








Irradiation of Skin with Visible Light Induces Reactive Oxygen Species and Matrix-Degrading Enzymes


• Skin contains several chromophores for visible light and the cumulative effects of visible light could result in skin damage, which may contribute to premature skin aging.


• Daily skin exposure to solar radiation causes cells to produce reactive oxygen species (ROS), which are a primary factor in skin damage. Although the contribution of the UV component to skin damage has been established, few studies have examined the effects of non-UV solar radiation on skin physiology.


• Solar radiation comprises of approx. 40-45 % of visible light (400-700 nm). Irradiation of human skin equivalents with visible light induced production of ROS, proinflammatory cytokines, and matrix metalloproteinase (MMP)-1 expression. The findings suggest that other portions of the solar spectrum aside from UV, particularly visible light, may also contribute to signs of premature photoaging in skin.


How Much Sun Protection is Needed?

Are we on the way to full-spectrum protection?


• Irradiation of skin cells with visible light, in doses comparable to 15–90 min of sunlight exposure, elicited a skin response similar to that induced by UV radiation, i.e., inflammation, ROS production, and the release of matrix-degrading enzymes.

• Liebel et al. (2012) did not find any thymine dimer formation (DNA damage) following visible light irradiation. However, 8-oxo-guanosin formation was found by Kielbassa et al. (1997) after irradiation of Chinese hamster cells with visible light. Maximum DNA damage occurred between 400 and 450 nm. More research is needed to investigate the exact contribution of visible light to DNA damage as most of the earlier studies were carried mout with mixtures of UV and visible radiation.

Learn More

How does it affect our eyes?

Does it harm our skin?


Can blue light filters affect sleep cycles?


© 2018 High Performance Optics, All rights registered.

©  2018 All Rights Reserved,  High Performance Optics, Inc.