Braille is the writing and reading system used primarily by the blind and those with severe visual impairments. This system is designed to be explored by touch; its basic unit is the cell. Within each cell a series of raised dots can be placed in six different positions. The different combinations of dots give rise to different letters, thus being able to represent all the letters of the alphabet, numbers, and even different punctuation marks (for a more comprehensive review see the Tutorial"Learn Braille in 10 minutes").

This reading and writing system, like any other, has a number of problems or difficulties that we will analyze below. With this, I don't want to present a pessimistic picture of the possibilities for blind people to access written information. Rather, I want educators to be aware of these difficulties in order to improve education systems.

Braille letters are made up of configurations of dots. The reader may make mistakes in identifying some of these dots. This will cause the reader to recognize a different letter than the one he or she is reading, whether he or she omits or adds a dot. For example, if he or she does not perceive the center dot of the letter "n" (⠝), he or she will identify it as an "m" (⠍). In addition, the sets of dots that make up some letters have a spatial configuration that often leads to confusion, due to the rotation of their configuration. For example, the letters "d-f-j-h" can be confused with each other, or the letters "n-z", or even "e-i". As is logical, these confusions can lead the reader to misidentify a word. In addition, the Braille system uses the same dot configurations for different signs. Numbers have the same dot configuration as the first ten letters of the alphabet; the reader can only distinguish them by a special mark that is placed before the number. Capital letters

are the same as lowercase letters (they use a special cell that indicates the capital letter). Undoubtedly, using the same configuration for different cells increases the difficulty of discrimination and, consequently, the problems of learning Braille.

Another problem with Braille is that accented vowels have dot configurations that are completely different from those of unaccented vowels. This poses an additional difficulty in learning to read and write. Children - or adults being introduced to Braille - must learn a special sign for each of the accented vowels. In addition, accented vowels have a rather complex configuration and can be confused with other letters of the alphabet, due to errors in rotation or addition or subtraction of dots.

Finally, I point out two additional problems in using Braille texts. A page written with this system takes up more than twice the space of a page written in ink. In addition, embossed writing paper takes up more volume than regular paper, which means the texts are heavier or take up more volume, making them difficult to handle and transport. In addition, texts written on Braille paper are easily worn out, due to repeated use, leading to legibility issues resulting in problems with comprehension and reading speed. The problems of paper-based Braille are partially overcome by using digitally reproduced Braille using electronic devices, including Portable ones.

These problems with the Braille system have led several authors to modify the code in an attempt to improve the reading performance of blind people. I can classify these modification attempts into three groups. First, shorthand Braille systems were created, with the goal of transmitting more information with fewer characters. Second, attempts were made to change the number of dots that make up the Braille cell. Finally, attempts were made to design a different reading code using raised Roman letters or a mixed code combining raised Roman letters and dots.

The amount of information that is perceived by touch is limited to the perceptual width of the fingertips, with all that that entails. Because of these characteristics of touch, the various experts in the field agree that one of the main problems of Braille reading is its "slowness". As we know, the average speed of an experienced sighted reader is between 280 and 350 words per minute. In contrast, the average speed of experienced adult Braille readers is no more than 130 words per minute, except in exceptional cases. This different speed is undoubtedly a "disadvantage" for blind people's access to written information, which has led to the search for different reading systems. One of these systems is the so-called "Audiobook", which consists of a recording of a text read aloud. Such recordings can be listened to at different speeds and are an alternative to read faster, although auditory reading poses another order of problems with important loss of information.

In any case, it is important to emphasize that although all the problems I have mentioned are real and must be taken into account when teaching Braille, this reading system is a fundamental and irreplaceable tool for the blind. Unlike auditory reading, people who read Braille achieve text comprehension similar to that of sighted people of the same age and educational level. Thus, from my perspective, there is currently no replacement system for Braille, although, as I have already mentioned, there are other complementary systems. Educational efforts should be directed toward improving the reading skills of this system as much as possible.

How do you read Braille?

Most blind people use their index fingertips to identify written characters. Although all fingers of the hand are capable of gathering accurate information from Braille characters, readers are generally limited to using their index fingers, with the exception of very skilled readers, who are also sometimes able to gather information with other fingers.

Braille readers make several movements. As readers become more adept at moving their hands along Braille lines, they modify the type of scanning they do with their fingers.

Beginning readers, when reading a line, move their fingers slowly, stopping continuously on the letters and making three types of movements: horizontal, vertical, and pressing. More experienced readers, on the other hand, make rapid, continuous, and uniform movements.

There are also differences in the type of hand movements that are made to scan the lines of text and to move from one line to another; we can classify them into the following types:

1. Unimanual scanning, in which only one hand is used to scan the text: the index finger of the left hand remains at the beginning of the line while the right one scans the text;
2. Joint scan, when both index fingers scan the line together, moving side by side;
3. Disjoint scanning, where the index fingers make independent movements along the line and then each hand scans different parts;
4. Simultaneous disjointed scanning, in which there is a period of time during which both hands read different parts of the line;
5. Mixed scanning which is a combination of joint and disjointed scanning. A movement where usually the left hand alone reads the beginning of the line, then both hands scan the middle part together until the left hand moves on to the next line and the right hand finishes reading the end of the line alone.

There are also several strategies for moving from one line to the next.

1. One-handed model, in which one hand makes the line change, either by moving backward along the line that was read, then moving down to the next, or by moving down to the next line and moving backward along it to its beginning.
2. One-handed model with indicator, when one hand reads and moves between lines while the index finger of the other hand is used as a guide in line changes.
3. Disjoint model, before one hand has finished scanning a line, the other hand moves to the next line.

But what determines the use of either pattern of hand movement and line switching? And is there any relationship between these patterns and reading performance? There appears to be a correspondence between reading level and the patterns of hand movements and line changes used in Braille. Thus, inexperienced readers read with one hand; as they gain more reading skills, both hands are used progressively until they reach the level of reading with both hands. The most effective method of achieving greater reading speed is one in which both hands are used, and more specifically, the pattern of movements that corresponds to "disjointed scanning." We should also keep in mind that it is not only the movement of the hands that determines reading speed, as subjects who perform this disjointed pattern are also very fast at identifying Braille characters.