F.lux – Help your Eyes

F.lux – Help your Eyes


F.lux is an innovative software application specifically created to promote better eye health and enhance sleep quality for individuals who spend significant time in front of computer screens. Its primary function is to adjust the colour temperature of your computer’s display following the time of day, an approach grounded in understanding how artificial light affects our natural circadian rhythms.

During the day, computer screens typically emit a bright, blue light that mimics daylight. This is beneficial for keeping us alert and focused. However, continued exposure to this blue light can disrupt our natural sleep patterns as evening approaches. Blue light is known to inhibit the production of melatonin, the hormone responsible for regulating sleep, which can lead to difficulties in falling asleep and overall poorer sleep quality.

This is where f.lux comes into play. As the evening progresses, f.lux gradually adjusts the display to emit warmer tones, reducing the amount of blue light. This shift mimics the natural progression of outdoor light, transitioning from the bright blue of midday to the softer, warmer tones of sunset. This can help in maintaining the natural rhythm of the body’s internal clock, potentially leading to better sleep quality and reduced eye strain.

The application allows for a high degree of customization. Users can adjust the level of warmth for the display, set specific times for the transition, and even choose different settings for various activities, like working, reading, or gaming. This flexibility ensures that f.lux can cater to individual preferences and schedules.

Moreover, f.lux is designed to be user-friendly. Once installed and configured, it runs quietly in the background, making automatic adjustments without the need for regular user interaction. This seamless operation makes it an unobtrusive but effective tool for managing the impact of screen time on one’s health.

However, it’s important to note that f.lux may not be suitable in all scenarios. For professionals who require precise colour accuracies in their work, such as graphic designers or photographers, the colour adjustments made by f.lux might be a hindrance. The application can be easily disabled or adjusted to accommodate these needs.

In summary, f.lux represents a thoughtful integration of technology and health science. Aligning screen colour with the natural light cycle offers a practical solution to mitigate the adverse effects of prolonged screen exposure, contributing to better sleep patterns and reduced eye strain, enhancing overall digital well-being.

Key Features and Functionality

  1. Automatic Screen Adjustment:

    F.lux changes the colour temperature of your computer screen according to the time of day. During the day, the screen displays normal colours. As evening approaches, it gradually reduces the amount of blue light emitted, casting a warmer, more amber light.
  2. Customization Options:

    Users can customise settings according to their preferences, including the level of warmth of the display, transition speed between day and night settings, and even setting specific lighting for different types of tasks like gaming or reading.
  3. Location-Based Timing:

    The software uses your geographical location to accurately time the screen adjustments with the local sunrise and sunset.
  4. Sleep Improvement:

    By reducing blue light in the evening, f.lux aims to reduce the disruption of sleep patterns. Blue light is known to interfere with the production of melatonin, a hormone that helps regulate sleep.
  5. Eye Strain Reduction:

    The warmer screen tones are easier on the eyes, especially in dimly lit or dark environments, potentially reducing eye strain and fatigue.
  6. Integration with Smart Lighting:

    Some versions of f.lux can integrate with smart lighting in your environment, matching your room’s lighting to your screen.
  7. Available on Multiple Platforms:

    Initially developed for Windows, f.lux is now available on macOS, Linux, and even on iOS devices through the App Store.


  • Improves Sleep Patterns:

    By mimicking natural light, it helps maintain natural circadian rhythms, potentially leading to better sleep quality.
  • Reduces Eye Strain:

    The reduction of blue light exposure, especially during evening hours, is beneficial for eye health.
  • Ease of Use:

    Once configured, f.lux runs in the background with minimal user intervention needed.

Limitations and Considerations

  • Color Accuracy:

    For professions relying on colour accuracy (like graphic design or photo editing), the colour changes can be problematic. However, f.lux can be easily disabled for colour-sensitive work.
  • Adaptation Period:

    Some users might take time to get used to the change in screen colour, especially when the settings are on the warmer end of the spectrum.
  • Mobile Device Limitations:

    On iOS, due to system limitations, f.lux provides limited functionality compared to its desktop counterparts.

Overall Impact

F.lux is a simple yet effective tool for anyone spending substantial time in front of screens, particularly in the evenings.

It addresses the growing concern of blue light exposure and its effects on sleep and eye health.

Its user-friendly interface and customisable settings offer a practical solution for enhancing digital well-being. While not a replacement for good screen habits, f.lux is a valuable tool for managing screen time’s impact on health.

I use it on all of my devices, and with appropriate lighting, I can work at all times of the day with minimal eye strain. See my other post about lighting here: – An Illuminating Subject


Hi, my name is Stephen Finchett. I have been a software engineer for over 30 years and worked on complex, business critical, multi-user systems for all of my career. For the last 15 years, I have been concentrating on web based solutions using the Microsoft Stack including ASP.Net, C#, TypeScript, SQL Server and running everything at scale within Kubernetes.