The Science behind Blue Light
Visible light is a form of electromagnetic radiation. The wavelength of the light defines its
colour and also its associated energy. Longer wavelengths have low energy and are grouped as
warmer colours whereas shorter wavelengths have comparatively higher energy and are
grouped as cool colours. Blue light has a wavelength of around 400 – 470 nm and therefore has
more energy when compared to the warmer yellow – red colours of 600 – 700 nm. The colour
temperature that indicates the colour tones of light is generally measured in Kelvins (K). Colour
temperatures over 5000 K are called “cool colours” or bluish colours and the values between
2000 – 3000 K is called “warm colours” or yellowish colours.
Research shows that the penetration capability of the high energy beams into human tissues is
relatively high than their lower energy counterparts. This very concept is used in the X-ray
Photography as well. X rays that are high in energy than the blue light are so intense that they
pass through the soft human flesh easily. Bones and other hard tissues block most of the X rays.
A film captures the variations in these X rays as shadows of those tissues & bones. Medical
professionals study the internal structure of these objects with the help of these X ray
Why is Blue light harmful for eyes ?
Blue light has more energy can easily pass through the very sensitive cornea, the lens and
finally, almost all of it is reached to the retina of the eye. Colours like yellow, Red being less
intensive, will be blocked more by the lens of the eye before they reach the retina. This is why
warmer colours are generally pleasant for the eyes than the harsher cooler colours. This is true
even with the blue light emitted from laptop screens. A blue light filter for laptop screens like
CareUEyes can completely block this harmful blue light and render a pleasant warmer
A continuous exposure of blue light from a laptop screen for extended periods of time leads to a
number of complications like dry eyes, headaches, eye twitches etc all of which are collectively
grouped under an umbrella term as Computer Vision Syndrome (CVS). As our eye is not able
to efficiently block most of the blue light, a long-term cumulative and constant exposure to this
high energy radiation will result in the damage and slow death of the cells of the retina. This
will accelerate the age-related macular degeneration (AMD) and ultimately results in a
permanent vision loss.
Blue light and Circadian rhythm
Human circadian rhythms have evolved to depend on the sun. We tend to be more active during
daytime when a lot of blue light is around us. During nights, our brain secretes a sleep
hormone Melatonin as a response to the absence of blue light. This hormone is very essential
for a good night’s sleep. High energy blue light also plays a major role in defining our mood,
activity and also sleep quality.
This very dependence of blue light for the regulation of circadian rhythm has made our bodies
evolve a special photoreceptor Melanopsin in the eye which is very sensitive to blue light. Light
as a factor now is very essential not only to our sleep but it acts like a synchronizer for many
other associated biological processes including temperature regulation as well. When the levels
of Melatonin rises in our body, as a response the body lowers its temperature and prepares for a
sleep phase. When Melanopsin receives blue light during the day, it triggers a response in the
brain to stop Melatonin secretion and our bodies come back from the sleep mode and become
active again. In this way, our entire biological clock runs on the basis of light.
Exposure to the artificial blue light especially from laptop screens during nights confuses the
body and distorts the circadian rhythm and thereby causes inability to fall asleep. This is the
very reason why it is difficult for people who work on the computer screen at night to fall
asleep. A constant exposure to blue light during nights keeps our brain at a higher activity level
for extended periods of time. This eventually leads to increased exhaustion, lack of focus,
anxiety and other complications which ends up in a lowered productivity. When the laptop
screen emits only warmer lights at night, our brain functions at a comfortable rate without any
disruption in the circadian rhythm and thereby decreasing sleep deprivation rate despite late
How can CareUEyes help us ?
Most computer monitor displays are designed to emit light that has blue colours around 6500K.
Laptop screens are primarily designed to emit a lot of blue light to create a natural daylight
effect on the screen. In order to protect our eyes from these harsher blue lights especially during
nights, a blue light filter for laptop screens in very much needed. Some hardware devices like
tinted screen filters can be used. Though they filter out blue light and other UV light from the
laptop screens, they also distort the text & images on the screen causing other complications
like “digital eye strain”. Aspects like different screen sizes may need different sized filters to
ensure a proper fit, need for a separate screen filter for every screen, complexity & bulkiness in
the usage and handling turns this option to become an expensive and complex affair in the end.
Another best way is to not use the laptop screens at all during nights. This isn’t a viable option
for working professionals, programmers etc who have to work late in the nights. An alternative
solution is very much required to suit the requirements of everyone.
CareUEyes is a lightweight, software version of the blue light filter for laptop screens. It
primarily runs on Windows OS. It runs in the background and does two things simultaneously
to constantly protect our eyes.
- It masks or “filters” the harsh blue light emitted from a laptop screen by shifting the
colour tones to the warmer parts of the spectrum.
- It lowers the brightness of the screen by changing the gamma value of the screen.
When these two things combined with the hardware screen brightness control of the laptop, the
user can get a pleasant viewing experience based on the contents of the screen and the
Unlike the hardware screen filters, CareUEyes works on multiple monitors irrespective of
their sizes and configuration. One needn’t buy any hardware devices like tinted screen filters,
special tinted eyeglasses or anything else to protect their eyes from the harsher blue light
emitted from the screens. The user can now comfortably work for longer durations without
causing much strain to the eye and body.
Will CareUEyes damage my laptop ?
CareUEyes monitors the laptop screen constantly and shifts any blue light to its warmer
counterpart before it is emitted from the screen. It almost works at the graphics delivery level
by hooking to graphics rendering interfaces. Despite this constant monitoring, the amount of
CPU resources it consumes is almost negligible. Even memory consumption is also very little
compared to other alternative softwares. At most it consumes just under 5MB of working
memory of the system.
One need not be apprehensive about the working of CareUEyes. Though it works at the
graphics rendering level, it won’t in any way manipulate any of the systems / hardware settings
or change any configuration of the system. When the program is terminated, it cleanly exits and
restores all the natural and original colour schemes of the laptop screen.
Brightness feature of the program is equally important. The user can vary the slider between
20% to 100% brightness of the screen. The basic principle behind the change of brightness of
the screen is not at the hardware level but the program cleverly modifies the gamma value of
the screen in order to manipulate the resulting brightness and thus in no way affects the
hardware configuration of the monitor at all.
Unlike other methods that employ running a constant script to lower the brightness of the
screen, it just alters the final gamma output of the screen and the end result is a lower brightness
without any flickers/dots on the screen and a constant brightness spread across the monitor.
So CareUEyes will be well suited even for CRT & TFT monitors as well along with the modern
LCD / LED screen. It works equally well in programmatically controlling the gamma level of
the monitors irrespective of their inherent structural design or working.
All in all, CareUEyes filters the blue light and shifts the colour spectrum to warmer pleasant
yellow light, it reduces the brightness gamma of the screen and reduces eye strain so in the end,
during nights, as exposure to the blue light is reduced, it helps our brain to secrete Melatonin in
good quantities thereby helping us to sleep better. A uniform shift of colour tones and a uniform
brightness on the screen ensures a seamless experience to the end user. All of this is done by
consuming minimal computing resources ensuring no impact on the overall performance of the
system. The resource footprint of the software is also constantly maintained to be negligibly
More on the features of CareUEyes
CareUEyes has two sliders on the Display menu. One to change the colour temperature and the
other to programmatically change the brightness of the screen. The user can also assign hotkeys
to both these functions to simultaneously change them on the fly. This very feature separates
CareUEyes from other software solutions. It just sits in the tray while running in the
background, a single click on the tray icon activates the sliders screen. The user can now vary
both the colour temperature and the brightness on the fly with just a couple of more clicks.
It has 8 preset modes like Office, Reading, Editing etc that suits to various purposes. Editing
mode is very useful for programmers who wish to work late in the nights. The mode basically
inverts the colours on the screen thereby stripping out the bright colour tones completely. Other
modes give a quick combination of temperature and brightness values depending on the
Hotkey for colour temperature changes the value by 55K and the brightness hotkey changes the
brightness of the screen by 4% for every keystroke.
Just by changing the slider the user can reduce the colour tones to as low as 1000 K and can
increase to the natural 6500 K of the laptop screen. CareUEyes is capable of handling this wide
range of 1000K – 6500K colour temperatures with ease.
A disable hotkey is also included to manually pause the CareUEyes working and restore the
original screen colours with the stroke of a hotkey. This is essentially useful for designers /
photographers/ artists who want accuracy of colours when they intend to use certain specialized
softwares. Rules can also be specified in the inbuilt rules manager to direct the working of
CareUEyes depending on the foreground software. When CareUEyes detects a whitelisted
software that is currently focussed / brought into the foreground / activated, it automatically
disables its working and the screen will have original colours till the software goes into the
The user still should have access to the hardware brightness control of the laptop screen to have
a complete and efficient control over the overall viewing experience depending on the ambient
It is recommended to change the colour temperature of the laptop screen to warmer values
when working late in the nights to prevent any distortions in the circadian rhythm / secretion
levels of Melatonin. If the user also sets a correct brightness level depending on the ambient
light, strain on the eye will be largely reduced thereby enabling the user to work for longer
The brightness value should be set such that the light from the screen matches with the ambient
/ indoor lighting. If the user works in a dark room with no ambient light, It is recommended to
set the brightness value to 20% and lower the laptop hardware brightness value to the
minimum. In other words, A laptop screen shouldn’t be the only source of light in the room.
Proper ambient light is equally important to reduce eye strain.
The very purpose of this article is to make one realize the harmful and cumulative effects of a
constant artificial blue light exposure particularly at nights from the laptop screens. In this era
of modernization, when computer screens have become an inseparable part of our life, an
efficient and a light weight blue light filter for laptop screens like CareUEyes, that can change
the colour temperature and the brightness, without compromising the systems resources, is a
great gift we give to our most precious eyes and to our overall wellbeing.
Looking for a night mode for pc?
CareUEyes is designed for people who like dark screens and want to protect their eyes. CareUEyes controls the brightness of the computer’s screen, when you work in a darker environment it can help you, It can dim all screens and monitors; LCD, TFT and LED backlit types, CareUEyes brightness dimmer for all versions of Windows, including Windows XP, Windows 7, Windows 8, Windows 10.
CareUEyes is an eye care software with night mode for pc , using this eye care software, you will be able to apply night mode to the computer screen in order to reduce eye strain. You can manually adjust the display color temperature and brightness to relax your eyes. Apart from that, it also comes with 8 different predefined filters based on various activities and you can apply them to your screen with just a click.
Unlike other night mode for pc, CareUEyes has higher performance. It only needs 5M of memory at run time, requires less CPU time. And the package of CareUEyes is only 2M. I believe this is your best choice.
How to blue light filter windows 7 in a simpler way?
CareUEyes can easily help you achieve intelligent blue light filter adjustment. Some software uses overlay translucent windows to filter blue light, but CareUEyes directly controls the display’s RGB value, which ensures compatibility with other software.You can also set the CareUEyes blue light filter adjustment feature to be disabled when a special program is running (for example, while running photoshop, to restore real color).
Unlike other blue light filter software on windows 7, CareUEyes has higher performance. It only needs 5M of memory at runtime, and it does not consume too much CPU time. And the package of CareUEyes is only 2M. I believe this is your best choice.
The blue light filter windows 7 cannot be adjusted. in addition to damage to the eyes, it can also affect sleep, Light is one of the most important external factors that can affect sleep. It does so both directly, by making it difficult for people to fall asleep, and indirectly, by influencing the timing of our internal clock and thereby affecting our preferred time to sleep.(External Factors that Influence Sleep)
How to avoid the effects of blue light
- Take regular breaks
- Take a 15-minute break. During this time you should blink, close your eyes, and allow them to rest and re-lubricated（CareUEyes break reminder feature forces you to take 3 minutes rest every 45 minutes by locking your PC for 3 minutes）
- Stop using all devices one hour prior to sleep
- Don’t take phones and tablets to bed. The blue light from your laptop’s display is more likely to keep you awake than the incandescent lamp on your bedside table.
How to adjust brightness on windows 7? Normally, open the windows 7 control panel, you can see the power options to change the brightness of the function, left and right drag change brightness slider to adjust the brightness of the display, But the brightness adjustment feature of Windows 7 doesn’t always appear in the control panel, even though we can’t adjust the brightness after we update the display driver according to the tutorial on the network.
CareUEyes can easily help you achieve intelligent brightness adjustment. Some software uses overlay translucent windows to adjust brightness, but CareUEyes directly controls the display’s RGB value, which ensures compatibility with other software.You can also set the CareUEyes brightness adjustment feature to be disabled when a special program is running (for example, while running photoshop, to restore real color).
The brightness of Windows 7 cannot be adjusted. in addition to damage to the eyes, it can also affect sleep, Light is one of the most important external factors that can affect sleep. It does so both directly, by making it difficult for people to fall asleep, and indirectly, by influencing the timing of our internal clock and thereby affecting our preferred time to sleep.(External Factors that Influence Sleep)
In addition, CareUEyes also has a Blu-ray filtering function, it can filter harmful blue light, so that you can get better sleep, auxiliary timing rest function to better protect your eyes, prevent eye fatigue.
What’s a better way to adjust screen brightness when windows 10 brightness not working?
Normally, if you open the control panel of windows 10, you can see the feature of changing brightness, and you can adjust the brightness of the display by dragging the change brightness slider to the left and right. But Windows 10’s brightness adjustment feature does not always appear in the control panel.
CareUEyes can easily help you achieve intelligent brightness adjustment. Some software uses overlay translucent windows to adjust brightness, but CareUEyes directly controls the display’s RGB value, which ensures compatibility with other software. You can also set the CareUEyes brightness adjustment feature to be disabled when a special program is running (for example, while running photoshop, to restore real color).
windows 10 brightness not working in addition to damage to the eyes, it can also affect sleep, Light is one of the most important external factors that can affect sleep. It does so both directly, by making it difficult for people to fall asleep, and indirectly, by influencing the timing of our internal clock and thereby affecting our preferred time to sleep.(External Factors that Influence Sleep)
In addition, CareUEyes also has blue light filtering features, it can filter harmful blue light, so that you can get better sleep, auxiliary timing rest function to better protect your eyes, prevent eye fatigue.
For people who work long hours in front of a computer, the eyes need more protection than the shoulders、 neck、back、waist and arms, because the eyes are an important part of our access to external information.
But for the windows system like windows xp、windows 7, change brightness is usually a troublesome thing, because it often requires more complex operations to darken the display brightness. Fortunately, windows 10 has introduced a new brightness change function. This makes it easier for us to change brightness.
How to change brightness on windows 10?
You can change brightness on windows 10 as follows:
using the Windows 10 Settings UI to control the brightness of your device. Go to ‘Settings’ and then select ‘System’. Now under ‘Display’, you will find ‘Change Brightness’ slider on the top. Move that slider to adjust the brightness of your device. (the slider bar may not be displayed for windows 10 with a lower version number).
Do you think that the change brightness feature of Windows 10 is perfect enough?
No, the blue light emitted by the monitor and the long-term use of the computer will cause more damage to the eyes.
CareUEyes can help you solve these problems. In addition to brightness adjustment, it also has a Blue light filter feature. It can turn the color temperature of the monitor into a warm color and reduce the damage caused by blue light to the eyes (such as IPhone’s night shift feature).
CareUEyes features a variety of working modes (smart mode, movie mode, reading mode, game mode), it is better to relieve fatigue in various modes.
It also has the break reminder feature. It can regularly remind you to take a rest, so that the eyes and shoulders、neck, back、waist、arm muscles are all rest,
These are unusual features, and hopefully they will help you.
People who have to work with computers in their daily lives and that covers most of us have started to become aware of the injuries caused to the carpal tunnel by strenuous work on the keyboard. There is a simple way to avoid it – take regular breaks and stretching your arms every few hours. Just like your shoulders, back, neck and the arms, you should also take care of the eyes. If you forget to do so, CareUEyes break reminder feature can ensure that you don’t forget to rest every now and again, by displaying desktop notifications for a specified amount of time.
The work and rest periods are fully customizable, and you also have the option of enabling a desktop timer that lets you keep track of how much time you have left until a break is due, and you can also choose to disable this feature.
If you want to ensure that you don’t keep skipping breaks when you have a lot of work to do, you can enable the “Force rest” feature, which prevents you from using your PC until the break is over.
CareUEyes break reminder feature forces you to take 3 minutes rest every 45 minutes by locking your PC for 3 minutes. You can customize this timer, and change the duration of rest and the frequency at which it appears. It gives you a form of snooze function so that you can delay the rest for a few minutes.When the rest time is 30 seconds away, it will show you a notification. On the notification popup, you will also see the option to delay the rest time by 3 and 5 minutes, as shown below
When the timer runs out, the software will lock your PC automatically for the time interval which you have selected as the rest time. The lock screen will simply show your desktop wallpaper along with the rest time remaining. If you want to continue your work, then simply hover the mouse cursor at the center of the screen and click on “Continue Work” button.
About Blue light
Blue light is a range of the visible light spectrum, defined as having a wavelength between 450−495 nm. This short wavelength means that blue light is a type of high-energy visible light, defined as having a wavelength between 380 and 500 nm. Violet, indigo, and some blue-green light are other types of high-energy visible light.
Blue light sources are becoming increasingly common in today’s environment. Exposure to blue light comes from a variety of technologies including computers, smartphones, televisions, and lights.
Effects of blue light on eye health
people are exposed to blue light via everyday technology, Blue light exposure has been shown to impact health. Some studies also suggest that chronic blue light exposure may represent a risk for the development of age-related macular degeneration and other pathologies. Animal studies have shown that age-related macular degeneration can be induced by blue-light exposure. One epidemiological study has also shown a positive correlation between sunlight exposure – a natural source of blue light- and increased risk of early age-related macular changes in humans. However, this particular association of effects from blue light is difficult to assess in humans and warrants further study. Unfortunately, there are no studies that measure the effect of chronic blue LED exposure on age-related macular degeneration in humans as this is relatively new technology
Effects of blue light on sleep and circadian rhythm
Natural exposure to blue light during the daylight hours boosts people’s energy, alertness, and mood. However, elongated exposure to the waves transmitted through screen devices during the evening can disrupt circadian rhythm and cause various health effects including a disruption in normal sleep schedules. Scientists believe this is caused by blue-light-sensitive intrinsically photosensitive retinal ganglion cells suppressing the production of melatonin and/or stimulating the suprachiasmatic nucleus of the hypothalamus
How to avoid the effects of blue light
More than half of U.S. adults – 60 percent – spend a minimum of six hours a day, every day on phones, tablets, and computers, so it’s important to practice good habits to keep your eyes safe from blue light
- Take regular breaks
- The American Optometric Association recommends that for every two hours of looking at the computer screen, you should take a 15-minute break. During this time you should blink, close your eyes, and allow them to rest and re-lubricated
- Use blue light reduction glasses
- Get fitted for blue light filtering lenses to block the penetration of blue light from computers and digital devices. They’re available for prescription and non-prescription glasses.
- Stop using all devices one hour prior to sleep
- Don’t take phones and tablets to bed. The blue light from your phone’s display is more likely to keep you awake than the incandescent lamp on your bedside table
blue light filter
CareUEyes is an eye care software with blue light filter ,screen dimmer and bread minder(rest timer). This software provides eye protection for those who use their computer continuously for hours. Using this eye care software, you will be able to apply blue light filter to the computer screen in order to reduce eye strain. You can manually adjust the display color temperature and brightness to apply the blue light filter and relax your eyes. Apart from that, it also comes with 8 different predefined filters based on various activities and you can apply them to your screen with just a click.
CareUEyes can automatically filter the blue light and make the screen look warmer and comfortable to the eyes so that your eyes do not feel tired. You can choose many presets and customize them for the blue light setting such as normal, smart, office, game and night etc
You can download CareUEyes from https://care-eyes.com
CareUEyes is a screen dimmer application that controls the brightness of the computer’s screen, when you work in a light or darker environment it can help you, It can dim all screens and monitors; LCD, TFT and LED backlit types, CareUEyes brightness dimmer for all versions of Windows, including Windows XP, Windows 7, Windows 8, Windows 10.
screen dimmer,brightness adjuster
The principle of computer screen brightness dimmer software:
The principle of the CareUEyes brightness dimmer is to use the software method to adjust the gamma value of the screen to make the computer screen brighter or darker. it will not damage your screen or monitor in any way.
The use of computer screen brightness adjustment software:
After installation of CareUEyes brightness dimmer, it will automatically increase brightness or reduce the brightness of the computer screen to protect the eyes, the default setting will reduce the brightness of 10%, and you can manually adjust it. Drag the progress bar to the left to decrease the brightness, the screen will darken, to the right to drag the progress bar will increase the brightness, the screen will light up.
When the CareUEyes brightness dimmer works, it will be displayed in the tray area and you have the freedom to set it up.
I am a software developer who will work longer hours in the evenings, and my laptop sends out great light, this was damaging to my eyes and I couldn’t work well, so I decided to develop CareUEyes brightness dimmer to solve this problem, now, at night, I do not have to worry about the problem of light too great, and I can freely adjust the brightness of the computer screen, hope CareUEyes brightness dimmer can be useful to you.