That button also lets you buy the book (in the case of a sample), skip to a specific page, bookmark, look up a word in the including Collins dictionary, view the book's table of contents, and adjust the font size -- there are eight font sizes in all.

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One programmer has taken it upon himself to provide a fix for the change to bring the font size back to less-squinting normal.

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Customers can touch to look up words, highlight passages and customize their reading experience by adjusting the font size and style, and experience lightning-fast page turns by swiping or using the device's contoured physical buttons.

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Most e-reading devices allow the reader to adjust the font, font size, contrast, column width, and other factors to compensate for impaired vision.

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Dr. Wolf, of Northwestern University, and other researchers, in partnership with the National Institutes of Health and the Agency for Healthcare Research and Quality, recently completed a trial testing a pill-bottle label that provides more explicit instructions and larger font size.

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Customers can look up words, highlight passages, adjust the font size and style or search by typing on the responsive on-screen keyboard that appears only when a customer needs it.

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