The right to vote in secret is a cornerstone of democracy, and is recognized as such by nearly all nations through their ratification of the International Covenant on Civil and Political Rights (ICCPR). The secret ballot is a feature of possibly every election law in the world.
However, the practice of elections in nearly every nation results in the blind citizen being dependent on another to cast his or her ballot. And logic tells us that a secret between two people is no secret.
If all citizens are to have equal access to the election process, then the election process must include procedures to enable blind citizens to cast a secret ballot.
It is surprisingly easy to do so.
In nations which use a paper ballot for voting, numerous jurisdictions have developed a ballot guide to help a blind voter independently mark the ballot. In most instances, this guide is a folder in which the regular ballot is inserted. The folder contains holes which correspond to the boxes on the ballot paper. On the folder are markers - sometimes Braille, sometimes raised bumps or lines - that help the voter navigate up and down the folder. Some election management bodies use a cassette tape as supplementary guide to the folder.
For examples of ballot guides from Mexico, see: http://www.electionaccess.org/en/resources/voter-education/tactile-ballot-guides/467/
In jurisdictions using electronic voting systems, markings in Braille may be used (Brazil) or a combination of Braille and synthesized voice. These approaches are becoming must more common in the United States, where federal law now requires all voting systems to be accessible to blind and disabled voters by no later than 2006.