Can’t Sleep? Blame Your LED Backlit Screen

Blue Lightwaves Disrupt Sleep But Improve CognitionA lot of studies have explored the potential negative effects of light pollution and overexposure to light. Some studies suggest excess exposure is related to insomnia (this might come as a shock…not) and diseases like Alzheimer’s or Breast Cancer. With regard to light wavelengths, the blue wavelength is one of particular interest, especially for those of us who use mobile electronics on a daily basis.

Melatonin & Blue Light

The New York Times published an article that quotes researchers who discuss some of the effects blue light has on our eyes and the chemical imbalance of melatonin. Melatonin is a hormone that responds directly to any kind of light. As night approaches and the amount of light decreases, the body releases melatonin, which “promotes sleep and alerts a variety of biological processes to the approximate hour of the day.” However, when light strikes the retina, or back of the eye, melatonin is suppressed.

…there lies the rub. In this modern world, our eyes are flooded with light well after dusk, contrary to our evolutionary programming. Scientists are just beginning to understand the potential health consequences. The disruption of circadian cycles may not just be shortchanging our sleep, they have found, but also contributing to a host of diseases.

Scientists like George Brainard, a neurologist at Thomas Jefferson University in Philadelphia, have observed that blue light is especially effective at suppressing melatonin. Why is this relevant? Many backlit electronic screens implement LED technology that uses blue wavelength emitting diodes.

The Experiments

A group of researchers at the University of Basel in Switzerland conducted a study using 13 men that were asked to sit in front of different types of computer screens before retiring to bed. During one week, they spent five hours in front a fluorescent, red-based screen that emitted little blue light. During another week, they spent five hours in front of a LED, blue-based screen that emitted twice as much blue light. Notice the first screen emitted barely any blue, so twice as much blue light is significantly more, but it doesn’t mean the screen was screaming blue. This is significant to me because it seems to indicate that the study was more realistic and not taken out of context from the kinds screens people actually look at. So what were the results?

Melatonin levels in volunteers watching the LED screens took longer to rise at night, compared with when the participants were watching the fluorescent screens, and the deficit persisted throughout the evening.

And this is the most intriguing part:

The subjects also scored higher on tests of memory and cognition after exposure to blue light, Dr. Cajochen and his team reported in the May issue of The Journal of Applied Physiology. While men were able to recall pairs of words flashed across the fluorescent screen about half the time, some scores rose to almost 70 percent when they stared at the LED monitors.

My first impression after reading that was that I’ll continue to study for tests using my computer. Maybe that explains higher tests scores when I do use my computer? I haven’t looked into it but it’s an interesting thought.


Again, why is this relevant? Because we are readily replacing old red light technology like incandescent bulbs with new energy-efficient blue light technology like LEDs. Most of our new electronic screens use LED technology (TVs, laptops, flat screen monitors, mobile phones, etc.).

Research isn’t absolutely conclusive since this is a relatively immature field of study, but the findings are starting to lead scientists to more concrete conclusions. Health agencies are starting to make statements. The World Health Organization concluded that irregularities in biological clock patterns “can alter sleep-activity patterns, suppress melatonin production and disregulate genes involved in tumor development.” The Journal of the American Medical Directors Association made conclusions regarding the boost in cognitive processes made by subjects exposed to blue light as opposed to red light.

Technological Solutions

If you’re a little paranoid about your health, or maybe you want to ensure you’re sleeping your best, there are some technological solutions. f.lux (Mac, iPhone/iPad, Windows & Linux) is a free program that automatically adjusts the amount of blue light emitted by your screen depending on the time of day. So in the evening the screen changes to redder tones. During morning hours, screen color is designed to emulate natural sunlight. Don’t worry, your whole screen won’t turn red; you’ll just notice a it feels a bit warmer with regard to color temperature. You can also customize it for the best experience by adjusting how fast it transitions, how much the color changes and what kind of lighting you are surrounded with.

I suggest you give f.lux a try as today’s mini-app of the day. I’ve found it rests my eyes a bit more in the evening if nothing else.

Another Mac only alternative is a prefpane app called Shades.

f.lux Screenshot

Examples of Other Light Related Studies

If you’re interested in learning a bit more you can check out the articles listed on Stereopsis’s research link (the group that developed f.lux) or read some of the studies listed below.

iPad App Review: Notes Plus vs. Notability

Notes Plus App for iPadVS Notability App for iPad

Since I recently acquired an iPad 2 (last October-ish), I decided I wanted to use it to take notes in some of my classes, mostly in ECON 110. We graph supply and demand curves 90% of the time in that class. Taking notes on my computer wasn’t practical; I tried making graphs in PowerPoint. I also tried using the pre-installed Grapher app that comes with OS X Lion. Nothing was really working for me. Drawing with a track pad is very tiresome. So I went ahead an bought a stylus on eBay for about $7.00 and started researching apps. The two apps I ended up trying are Notes Plus and Notability.

(If you don’t want to read about my experience, just skip to the Epilogue: General Features & Screenshots)

Notability: An Impulse Purchase

I first purchased Notability because I saw it was “on sale” for a couple days and bought it for ~$1.99. I was very impressed with most of the functionality.

My greatest disappointment was adding figures and drawing. In order to draw with this app you have to insert a figure. In other words…

While all other functionality was more than satisfactory, I felt like I really needed an easier way to draw straight into my notes. So I spoke with a friend of mine who also has an iPad and who I had seen using it to take notes in some of my classes. He recommended Notes Plus.

Notes Plus: Referred by a Friend

So I give my friend a short demo of Notability and then let him try it out for himself. He seemed reasonably impressed and didn’t have anything really bad to say about it. Then he gave me a short demo of Notes Plus. It seemed pretty comparable. They had some different approaches to the same problem but both were well executed. However, what caught my eye most was that with Notes Plus you can draw straight into your notes. No extra, separate figures. AND it has great options for automatically detecting, smoothing and straightening lines and shapes. I bought it and downloaded it within the hour.

My first fuss with Notes Plus was that the drawing/note-taking space wasn’t big enough. I had to keep adding more pages to my economics notebook. However, that was just a dumb move on my part. There is actually an option for making the pages bigger. So I tried that for a while. It worked great.

My biggest beef came down to this: my hand writing is so sloppy even with a stylus that writing out notes on the iPad was messy and inefficient. Even with the gorgeous character smoothing, it just wasn’t enough. I would write and undo and rewrite and erase and…yeah. And as easy as adding textboxes is in Notes Plus, it just isn’t simple enough or hassle-free. It takes a lot of extra time to move the text boxes around and resize them. In the end, I was getting more and more behind in my notes and I never had time to really focus on what the professor was actually lecturing on. I spent all the time people were asking questions just catching up. Eventually, I decided I would just have to resort to the old graph paper notebook.


So it’s a sad story of how I fought the battle of traditional mediums vs. technology. But if tech just doesn’t do the trick, why bother? Why inconvenience yourself? Besides, my wife still uses the apps to draw, and I’ve found they are great for other things like entertaining children at church or visiting nephews. Though, I’ve found better drawing apps for that too…

Something worth noting about both apps is that they can sync your notes to Dropbox.

For all general purpose note-taking (when I don’t need to draw), I use Evernote or Simplenote because they sync to my existing accounts online where I store all my notes. What has been your experience with note-taking on the iPad? What works for you?

Epilogue: General Features & Screenshots

I’ve included the primary features (as described by the developers on the AppStore) for those of you potentially interested in either of these two apps.

Notes Plus

Hand write comfortably with your big finger, your text will show up as fine as with pen and paper. Auto-advance feature let you write even with your eyes closed. Advanced stroke smoothing algorithm makes your writing look as good as ever; the faster you write, the better it looks.

Lay your palm comfortably down with Palm Pad.

Let you insert keyboard text anywhere on the page with many type faces, font sizes, and colors.

Let you draw a basic shape (ellipse, rectangle, line, polygon, …) with your finger, auto-detect and insert the perfect vector shape, then let you edit it.

Let you record audio while jotting down the note. Perfect for meetings, classes, or conferences. Recordings are linked with pages to provide easy playback.

Let you select handwriting text by just circling around it, then erase or re-arrange it. Erasing a writing is as easy as drawing a line over it. No awkward switching between erase tool, selection tool, and draw tool.

Provide a complete folder structure. Private folders can be password-protected. A folder can have many notebooks; a notebook can have many pages. Pages are listing with thumbnails. Provide ability to move, copy, duplicate and delete notebooks or individual pages.

Full undo/redo support. Yes, it does have REDO function; touch and hold undo button to reveal the undo/redo action sheet. Also let you recover your deleted notebooks or pages.

Many options are provided including: stroke color, thickness, transparency; text font, size, color; paper background, etc.

As you can see from the screenshots below, this app stands out for its clean interface. A great effort was put in to hide controls so that it would not cluster the interface. You should be able to start without a tutorial.

The developer encourages you to email him with any questions concerning features since he has only listed his “top 10.” It might be worth your time since he tries to respond to all emails within 24 hours.


** Full-featured Handwriting **
Amazingly smooth ink makes capturing ideas easy and awesome. Notability’s zoom window helps you quickly and clearly draw every detail and the palm rest protects your notes from unwanted marks. Our scissors let you copy, move and even re-style the color and width of any ink. Reordering notes is a joy: drag-and-drop thumbnails, while adding or removing pages as needed. Your notes should be as unique as you are, so choose a paper to fit your style and use a variety of pen colors and widths to create beautiful notes.

** PDF Annotation **
The same tools that help you take beautiful notes in Notability equip you to annotate PDFs: record, type or handwrite on anything. It’s easy to share your annotations with anyone using email or Dropbox and more.

** Advanced Word-Processing **
Notability’s features like styling, outlining, and spell check are the perfect tools to get the job done quickly and accurately. Other tools like bullets, bold, italic, underline, font presets, cursor controls, and more, seamlessly integrate to help you create rich notes.

** Linked Audio Recording **
Audio recordings automatically link to your notes, so go ahead and take notes with confidence. While reviewing your notes, just tap a word to hear what was said at that moment. Our advanced audio processing features create brilliant recordings in any setting. Use the recording feature to capture your own voice for memos, presentations, or speech practice.

** Auto-sync **
Work with confidence: with Notability’s auto-sync, your notes are always backed up in the cloud. Easily collaborate at work or school sharing ideas and notes on the fly.

** Media Insertion **
Enhance your notes by adding pictures from your photo library or from the iPad camera. Insert web clips, figures, and drawings to compliment your notes. Crop, resize, and draw on images to make them perfect. Your text will automatically flow around them.

** Library Organization **
Your ideas and notes are incredibly important to you, so Notability makes it simple to organize, protect and share this information. Drag and drop notes into a subject and use a password to keep notes secure. Auto-sync makes backing up simple: your notes are automatically uploaded to Dropbox, iDisk or WebDAV. Import notes, PDFs, and RTFs from the cloud or web. And share notes via Email, Dropbox, iTunes File Sharing, and AirPrint.


Notability - Mainscreen

Notability – Mainscreen

Notes Plus - Notebooks

Notes Plus – Notebooks 

Notability - Writing

Notability – Writing

Notes Plus - Writing

Notes Plus – Writing

Notability - Note Taking & Figures

Notability – Note Taking & Figures

Notes Plus - Drawing Figures

Notes Plus – Note Taking & Figures