A currency reader, called the iBill, is available for the Blind and Visually Impaired, at no cost, from the Bureau of Engraving and Printing.
Below is the information from their website:
All U.S. citizens, or persons legally residing in the U.S. who are blind or visually impaired can request a free currency reader from the Bureau of Engraving and Printing by downloading the application below. The application is provided in both English and Spanish. The application must be filled out completely, signed by a competent authority who can certify eligibility, and returned to the mailing address provided on the form.
To request a currency reader, individuals must simply fill out and mail in an application form, which is available for download on BEP’s website at http://www.bep.gov/uscurrencyreaderform.html or by calling the U.S. Currency Reader Program office toll free at (844) 815-9388 and request that an application be mailed to you.
An EyeNote app for the iPhone is also available. Below is a YouTube video with more information.