How Braille Works

In 1828, Charles Barbier, a visitor to Royal Institution for Blind Youth, introduced Louis Braille to a tactile dot code known as night writing. Barbier had invented the code to allow soldiers to communicate with one another in the dark, but his idea hadn't caught on. It used dots to represent 36 phonetic sounds rather than the letters of the alphabet. Some of its characters were six dots tall.

Louis Braille realized that the same basic idea could give blind people an efficient method for reading and writing. Through trial and error, he figured out that a six-dot cell was small enough to fit under a fingertip but had enough possible dot combinations to represent a wide range of letters and symbols. He used this cell to create an alphabet using tactile dots and dashes.

The Braille cells used today are two dots wide and three dots tall, and they no longer use dashes. You can represent each dot's position within the cell with a number. Dots one, two and three are on the left side of the cell, and dots four, five and six are on the right side. A cell with one dot in position six indicates that the next cell represents a capital letter, and a cell marked with dots three through six signifies that the next cell represents a number. The Braille characters for the numbers zero through nine are the same as for the letters "a" through "j."

A typical line of Braille is about 40 characters long, and a typical page of Braille is about 25 lines long. In other words, Braille takes up significantly more room than standard-sized print. Braille pages are also thicker and heavier than ordinary paper, and they have to be bound in a loose format so that pages can lie flat and people can reach the cells near the book's binding. This leads to relatively bulky books. For example, the Braille version of "Harry Potter and the Half Blood Prince" is eight volumes long. Its longer predecessor, "Harry Potter and the Order of the Phoenix," is fourteen volumes long.

To conserve space and make the reading process a little faster, many people learn to read contracted Braille, previously known as Grade 2 Braille. Uncontracted Braille, or Grade 1 Braille, uses characters to represent single letters, numbers and symbols. Contracted Braille uses characters to represent letter combinations or whole words. There are close to 200 contractions in the American version of English Braille. These include commonly-used words like "and," "you" and "for" as well as letter combinations like "ing" and "ed."

There are opposing theories about whether it is better for a person to learn contracted or uncontracted Braille. Some educators argue that uncontracted Braille is an important foundation for learning contracted Braille. In addition, learning characters for individual letters and symbols may be easier for young children who are beginning to learn to read. Opponents argue that uncontracted Braille is more time- and space-consuming than contracted Braille and that teaching the contracted version first requires people to learn two codes.

People read Braille by moving their fingertips from left to right across the lines of dots. When writing Braille, people move from right to left instead, physically pressing the dots into the paper so that they show up on the other side. There are many methods used to write Braille, including:

Learning to use these tools and to read Braille is a lot like learning to read and write print. Printed letters and Braille cells are both symbols for pieces of language. The first step is to learn each of these symbols and what they mean. The next is to learn to recognize the patterns that the letters form. This eventually leads to the comprehension of words, sentences and paragraphs.

Many blind children learn to read Braille using primers much like their sighted classmates. However, many of these primers rely on pictures to help children grasp the meaning of words. Children who do not see well enough to decipher pictures don't get this additional context to help them learn. For this reason, many teachers combine basic reading primers with organized Braille literacy curricula. Several companies create these curricula, which include charts, stories and teaching tools. Some curricula are deigned specifically for children, and others are more suited for adults. Check out this reference circular from the National Library Service to learn more about them.

It's a lot faster to write in Braille than it is to create the embossed letters used in some earlier tactile writing systems. However, creating books in Braille still takes time. Until recently, translating a book from print to Braille required sighted transcribers to translate the book by hand. In some cases, this could take hundreds of hours. Improved optical character recognition (OCR) technology and computerized Braille printers have improved this process significantly. Rather than copying a book by hand, people can scan books, translate the scanned text to Braille and print an embossed copy.

Reading Braille can also be a little slower than reading print. People who are fluent in Braille can typically read at a rate of 125 to 200 words per minute [Source: American Council of the Blind]. On average, eighth graders read at a rate of 205 words per minute, and college students read at 280 words per minute [Source: University at Buffalo]. To make up for the difference in reading speeds, many people who know how to read Braille also use other methods to gain information. These include:

A six-dot Braille cell allows 63 possible combinations of dots. This might sound like plenty -- after all, the Latin alphabet as used in English has only 26 letters, and you can represent any real number with the numerals 0 through 9. But in addition to letters and numbers, there are a wealth of punctuation marks. Then, there are symbols used in science and math and musical notes that also need Braille counterparts. Basically, anything a sighted person could read from a printed piece of paper needs to have a representation in Braille.

For this reason, many languages have multiple Braille codes. For example, in the United States, the Braille Authority of North America (BANA) publishes standards for several codes, including:

A few specialized codes use eight-dot cells rather than six-dot cells. For example, an eight-bit ASCII code uses one Braille character to represent each ASCII character.

Braille characters can have multiple meanings depending on which code is being used. While this is necessary to make 63 combinations of dots to represent an infinite range of letters, numbers and symbols, some people find learning multiple codes to be confusing. For this reason, the International Council of English Braille (ICEB) has created Unified English Braille. Unified English Braille includes symbols for literary material, math, science and computers. In other words, it consolidates three other Braille codes.

In addition to reducing the number of codes people have to learn, Unified English Braille has the potential to standardize Braille for all English-speaking countries. A few countries, including Australia and New Zealand -- which used to use English Braille, American Edition -- are transitioning to it from other systems. Currently, Great Britain and the United States continue to use their own systems. In Great Britain, the Braille Authority of Great Britain (BAUK) publishes Braille systems. The British and American systems have essentially the same alphabets but use different notations for science, math and computers.

Reading other languages can also require learning additional Braille codes. Even languages that use the same Latin letters that English uses often have their own specific letter combinations and contractions. Welsh, for example, has several two-letter combinations represented with one Braille cell.

Braille characters can represent virtually any language, regardless of how that language is written. In Chinese Braille, the characters represent the sounds that make up the spoken language. Hebrew Braille uses cells to represent the letters of the Hebrew alphabet and contractions specific to that language. Tibetan Braille is one of the newest Braille codes. Sabriye Tenberken created the code so that she could read Tibetan manuscripts independently. She then traveled to Tibet to teach blind Tibetans to read and write in Braille.

Along with entirely new Braille codes for different languages, there are ongoing efforts around the world to standardize and improve Braille. Many countries have departments and agencies that continually evaluate their Braille codes and suggest changes or improvements. In addition, technological changes can also affect Braille. Improved materials and circuitry have led to more effective refreshable Braille displays, which can continually display lines of text translated from computer screens and e-books. New display prototypes can be rolled up like paper. Web-Braille allows libraries to download and print Braille materials rather than wait for them to arrive in the mail. In the future, Braille books, magazine displays are likely to become more efficient and flexible, as well as less expensive.