Apple has been making huge strides in bringing accessibility to iPhones and iPads. Visually impaired users are able to use iPhones by using voice and touch support. Interestingly, iOS devices support Braille access which is not a possibility yet in many popular smartphones and tablets. With every new upgrade, Apple adds more accessibility features to it devices. iOS 7, its most recent upgrade, comes with a number of feature supports for Braille users on iPads and iPhones.
Read more about it here: http://www.aeldata.com/blogs/item/142-journey-towards-braille-with-ios-7