Is Reading on an eReader Bad for My Eyes?

That question was posed in the March issue of Real Simple magazine.  Considering the growing popularity of ebooks, it's a good question to ask.  The answer is quite interesting.  Note the explanation in Real Simple:

"Not in moderation," says Harvey Moscot, a New York City-based optometrist.  The article goes on to report: "If you spend a long period (more than two hours) staring at a screen - on an ereader, a smart phone, or a laptop - you could suffer from what is sometimes called computer vision syndrome (CVS), a repetitive-stress condition characterized by some uncomfortable side effects, including headaches, blurred vision, and eyestrain."

To prevent CVS, some ereaders use electronic ink, which has sharply defined type and is easy on the eyes.  Reading on electronic ink devices most closely resemble reading on paper.  Our eyes tolerate reading on paper the best.  Other ereaders have a backlit LCD screen, similar to a computer monitor.  Even though these devices emit their own light, it is suggested that you use a lamp.  A stark contrast between the screen and your surroundings is hard on the eyes.  Moscot also suggests taking short breaks.  He recommends the 20-20-20 rule - after 20 minutes of reading, focus on an object 20 feet away for 20 seconds.