For Seniors: Adjust Brightness and Change Font Size and Type in iBooks
iBooks on your iPhone 4S offers an adjustable brightness setting that you can use to make your book pages comfortable to read. If the type on your screen is a bit small for your taste, you also can change to a larger font size or choose a different font for readability.
To adjust the brightness setting in iBooks, follow these steps:
With a book open, tap the Brightness button.
On the Brightness setting that appears, tap and drag the slider to the right to make the screen brighter, or to the left to dim it.
Tap anywhere on the page to close the Brightness dialog.
Experiment with the brightness level that works for you, or try out the Sepia setting in the Fonts dialog. Bright white screens are commonly thought to be hard on the eyes, so setting the brightness halfway to its default setting (or less) is probably a good idea.
To change the font size and type, follow these steps:
With a book open, tap the Font button (it sports a small letter a and a large capital A).
In the Font dialog that appears, tap the button with a small A on the left to use smaller text, or the button with the large A on the right to use larger text.
Tap the Fonts button. The list of fonts shown here appears.
Tap a font name to select it. The font changes on the book page.
If you want a sepia tint on the pages, which can be easier on the eye, tap the On/Off button to turn on the setting.
Tap outside the Fonts dialog to return to your book.
Some fonts appear a bit larger on your screen than others because of their design. If you want the largest fonts, use Cochin or Verdana.