In recent years more and more so-called reading devices for reading electronic books have gained popularity among people. Not so long ago we didn't hear about it, and now, especially after the release of the Apple iPad on April 3, 2010 (one of the key features that - simply reading a book), the popularity of readers has grown to a level unprecedented scale that didn't exist before. People read, read and will read books. Life goes on. Books have also undergone changes: first they were on bark and papyrus, then on leather and paper, but now we have e-books. First, there are three types of digital books:1. Economical e-reader with color TFT screen. The advantage is the price, the disadvantage is high power consumption and dubious safety for the eyes. After prolonged reading with a bright TFT screen, the eyes can feel very tired if the reader does not periodically take breaks. The problem is flickering lighting, which is a key part of TFT technology. To distinguish the TFT screen you need to look from a certain angle, which has a viewing angle of 90 degrees. This creates some discomfort, especially in full sun.2. Readers based on electronic ink (E-Ink technology). It is considered safe to look at, consumes little energy due to the technology used. It performs the same function as the first category, but has a monochrome image. E-books with E-Ink displays allow you to read as much as you want, because if you read them in the light there will be no eye irritation. It can be concluded that E-Ink screen is safer for the eyes. The viewing angle of any E-Ink screen is 180 degrees, which allows you to easily read text from any angle, even in bright sunlight. H...... middle of paper ......y- because instead of carrying a lot of heavy books we carry a light tablet that has everything we need. And the last but not least factor is the environment. Without e-books, 125 million trees would be cut down every year and over 40 million tons of CO2 would be emitted every year; equivalent to the annual CO2 emissions of 7.3 million cars. However, e-books do not harm nature because no tree is needed for the production of digital book, moreover, before if some allergic people could not read a book due to dust, now it is not a problem and they can easily read a book digital! Personally, I love reading and that's why I bought a cell phone that has a large screen, through which it is very convenient to read books in electronic format. Remember, the main rule is to read digital books with breaks and only then it will not harm your eyesight!