NEW YORK (TheStreet) -- Your three-year-old kid is probably looking at e-books and that's okay because, despite popular claims, digital books won't turn his or her brain to mush.

Kids are also increasingly learning digitally. Some 30 million students and faculty are using Google's (GOOG) - Get Report Chrome educational tools and sales of Chromebooks used for education spiked in 2014, according to research firm IDC. At children's publisher Capstone Publishing, sales are now more than a third digital, up from less than half that several years ago, with much of the growth coming from educational and institutional sales, according to Ashley Anderson Zantop, the publisher's chief content officer.

The digital reading trend among children is growing fast. Two-thirds of kids between the ages of two and 13 read -- or are read to from -- ebooks, according to 

The ABC's of Kids & E-Reading

, a recent study from research firm Play Science and Digital Book World. That is up from

54% two years

 ago. Further, 41% of kids prefer reading e-books to physical books, compared with 27% who prefer the opposite. Today, one in five children's books sold is an e-book, according to data from


 BookScan, up from one in seven a year ago.

But don't fret for the screen-addled brains of the nation's youth.

Despite years of reports of angsty parents uncomfortable with putting their children to sleep to warm glow of an iPad, evidence that digital reading is bad for your kids is scattered. The American Academy of Pediatrics' recent recommendation that children under two-years-old have no "screen time" is not based on any data, the organization has admitted. A recent New York Times article cited several studies that suggest a parent and child reading a print book together has added benefits over doing the same in digital.

Yet, none of these studies compared the effects of children reading alone digitally and in print; and none of them compared digital reading to no reading at all, which is what children's book publishers -- and


(AMZN) - Get Report

 -- see as the reality.

"Any literacy experience for a young child is a good one," says Jennifer Perry, vice president of worldwide publishing for non-profit Sesame Workshop, which publishes print and digital titles based on familiar characters like Elmo and Big Bird.

Perry led a chorus of publishers at the Digital Book World Conference in New York this week who see other media more as a threat to reading and learning. "Anything that encourages a child to read is great," says Jillian Ports, an editor at publisher Astor + Blue Editions.

On this issue, publishers and Amazon are in lock-step.

"Books don't just compete against books. Books compete against Candy Crush, Twitter, Facebook, streaming movies, newspapers you can read for free," Russell Grandinetti, Amazon's senior vice president for Kindle, told the Timesin July 2014. "It's a new world."

It's a world that books -- digital or otherwise -- may be losing.

Sales of both digital and physical children's books have been rising in recent years, but once children reach a certain age, reading drops off significantly.

"Older kids are not reading as much as they used to," says Jonathan Nowell, president of Nielsen Book. "They have less time and far more choice."

Some two-thirds of teens in the U.S. told Nielsen that they read for fun in the fall of 2014, down from 81% in the spring of 2012.

Whether it's because they abandon reading altogether or because they port the digital reading habits of their youth to adulthood, infants born today may never think of "books" the way most of us have always thought of them: paper, ink and glue.

"It's adults who identify a print book as a 'book.' When you say 'book' to kids, it could be a digital app, an iPad, anything," says Sesame's Perry.