Read this: Though still predominantly green, post-2004 series incorporate other colors to better distinguish different denominations. As a result of a 2008 decision in an accessibility lawsuit filed by the American Council of the Blind, the Bureau of Engraving and Printing is planning to implement a raised tactile feature in the next redesign of each note, except the $1 and the version of the $100 bill already in process. It also plans larger, higher-contrast numerals, more color differences, and distribution of currency readers to assist the visually impaired during the transition period.

Who are currency readers meant to assist?
What is the answer? (If it cannot be answered, return "unanswerable")
visually impaired