Dubious Blue Light iPhone App
Recently a press release crossed my desk advertising a blue light application for your iPhone (now) and for the Blackberry and Palm soon. I was amazed at the brash medical claims this software maker was claiming — claims that one might think might need to evaluated by the Food and Drug Administration because they relate to the claimed treatment of seasonal depression.
What’s so special about blue light?
In recent years, there’s been a growing body of research that suggests light in the 460 – 470 nm wavelength spectrum can be particularly effective in helping people with seasonal affective disorder (also called seasonal depression or SAD). It’s also been theorized to help fight fatigue and drowsy driving.
But here’s the rub. When you examine those studies, you find that it’s not only the wavelength that’s important, but also how much of the light you’re getting (e.g., what’s the lux output of the light device). In the research, the lux ratings of the devices used range from 398 lux to 1,350 lux for at least 30 minutes per day (and in some cases, much longer).
The new software application from the press release is available only for cell phones. Guess what the lux output on cell phones is? According to tests conducted by WirelessInfo.com:
- Apple iPhone 3GS – 133
- Apple iPhone 3G – 207
- Apple iPhone – 168
- Blackberry 8800 – 90
- Helio Ocean – 63
- LG Prada – 43
- Nokia N95 – 72
- Palm Treo 750 – 60
So assuming you’re using the latest iPhone 3 GS, you might need to sit in front of the application, close to your face, for up to 3 times as long to get the same benefits that clinical studies have shown. There have been no clinical studies that I could find that used such low lux output blue light.
In contrast, the the press release trumpets:
In just 15 to 30 minutes a day, this application invigorates your mind and body as well as expensive light boxes.
In the actual research, the minimal amount of time in front of such devices was 18 minutes — with light output that was more than twice as bright as an iPhone. Most studies done on blue light required the participants to get between 30 and 45 minutes of exposure, every day. Participants were sitting 1 to 2 feet away from the light source in this research.
So you’d think they’ve done their own clinical studies to actually examine a cell phone’s effectiveness using this software. On the “Clinical Studies” link on their website, they link to such rigorous journals as CNN Health, and Modern Medicine. None of the links demonstrate the use of this particular software, but are instead about the potential uses and benefits of clinically-tested blue light therapies. The one study that comes close to providing evidence for their software was never published in a peer-reviewed journal (it’s a “white paper,” meaning its methodologies were never subjected to professional scrutiny).
Without apparently any original research of their own, their CEO makes the following claims about their software:
The light is effective when placed anywhere within four feet of your face at any angle. You can lean it up on a phone stand or lay it on your desk or kitchen table. It’s also highly effective for long road trips and night driving without interfering with the driver’s vision. This application is also great for college students who need to focus for late night study sessions.
It is highly dubious that anything this guy is saying is based upon research conducted using the software he is actually selling.
Blue light in the 460 to 470 nm spectrum does indeed show strong clinical evidence that it can be effective in helping treat seasonal affective disorder. But it’s probably a stretch to say that you can replicate these clinical results on low lux devices like cell phones. Unless, perhaps, you have the phone within a foot or two of your face, and you stare into it for 45 minutes a day.
Grohol, J. (2009). Dubious Blue Light iPhone App. Psych Central. Retrieved on May 29, 2015, from http://psychcentral.com/blog/archives/2009/08/21/dubious-blue-light-iphone-app/