Less than five per cent of new books are made available in such formats. The treaty will commit signatories to amend national laws so works can be translated into alternative formats without need of a copyright licence.
Although this might look like a technical measure, the World Blind Union — rightly — regards it as a humanitarian move, because it will enable more of the world's 285 million blind and visually impaired people to access previously unavailable information.
As with other commitments designed to benefit disabled people, this treaty alone will not unlock that information. Investment is needed to identify and translate useful and interesting texts.
Visually impaired people and their representative organisations repeatedly ask why publications are not produced in accessible formats when they are published. It is frustrating and time-consuming for visually impaired people to request suitable formats for books they want to access, especially as these are generally denied.
The main answers given for this failure relate to perceptions of high cost and low demand.
But these reasons are no longer legally valid in the 134 countries that have ratified the UN Convention on the Rights of Persons with Disabilities, which says information and communications should be universally accessible. 
Establishing good relationships with local Braille producers would accelerate production times and could reduce costs by allowing Braille versions to be produced on demand.
In addition, new technologies are reducing production costs.
Most non-disabled people perceive Braille as the only format for accessibility. But there are relatively few Braille users worldwide — for example, only one per cent of the UK's visually impaired population uses it  — so ignoring other formats, such as audio and large print, excludes millions of non-Braille users.
Good guidelines on improving accessibility include those by the International Disability and Development Consortium and Britain’s Royal National Institute of Blind People. [3, 4]
The World Wide Web Consortium produces accessibility standards for all those producing text for the Internet.  Producing all text in fonts and formats for easy screen reader use is a low-cost measure.
Audio versions can be easily stored as mp3 files on websites.
This treaty paves the way for new technologies on accessibility to be used more widely. I hope they will be.
Sue Coe has worked in international development for 25 years across Africa, Asia, Europe and the Middle East. Now a development and disability inclusion consultant, she previously worked for World Vision, Practical Action (formerly ITDG), VSO and Action on Hearing Loss (formerly RNID). Coe can be contacted at email@example.com.
 UN Convention on the Rights of Persons with Disabilities (UN, 2006)
 Rose, D. Braille is spreading but who's using it? (bbc.co.uk, 13 February 2012)
 Wolhandler, J. IDDC Accessibility Manual (IDDC, 2013)
 RNIB Accessible information (RNIB, accessed 13 September 2013)
 Shadi, A.-Z. et al. Accessibility (World Wide Web Consortium, accessed 13 September 2013)