The WHO defines blindness as "visual activity of less than 3/60, or corresponding visual field loss to less than 10 degrees, in the better eye with best possible correction" (Bonet-Borrás & Muñoz-Sevilla, 2007).
In the ever advancing modern society, the role of the visually impaired person is growing with an increase in the interaction of the visually impaired person with the general society. But still the blind face major hurdles for functioning as a cog in the society. The problems faced by the blind can be broadly classified into two major categories (Hardwick et al., 1998)
1. The ability to move about independently which brings in the use of the latest navigation and mobility aids.
2. The ability to access information available in the society which includes the digital information available on the web.
Navigation And Mobility Aids:
The First and the most ancient “technology” used to help the blind navigate without a natural human aid is the simple white cake. It is a simple aid which the user can use to detect obstacles and explore the cone of space within its reach. The use of guide dogs to help the blind navigate is also in use for some time now. The earliest record of the use of guide dogs dates back to the late 18th century (Upgrade web).
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With the electronic revolution and boom in the use of electronic devices as mobility aids has increased in an exponential rate.
In normal day to day life people use a vast range of visual information for navigation both in the indoors or outdoors, using public transport like text and/or symbols which indicate the access for a wide variety of bus lines, posters and other facilities. Performing these day to day activities becomes high difficult or some cases impossible for people with visual disabilities. They must try to infer and interpret this information by other senses or by asking sighted people to help them. This becomes a problem as this means that they will have to depend on the patience of others around them to perform even the simple basic, everyday tasks (Krahe, 2007). Various modern technologies are being implemented in order to help the visually impaired individuals to be able to function independently.
This technology can be as simple as installing simple Braille and tactile signs to the most recent advancements including the attempt to create a virtual environment which would help the user to get acclimatised to a work space before actually entering and using the space.
The Disability Discrimination Act of 1995 (UK) aims to guarantee equal access to all people using public buildings. This legislation was fully enforced in the UK by the end of 2004 (UK Plastic Fabrication). This means that tactile and Braille signs will have to be used by law in public buildings including offices, factories, hospitals and hotels on all facilities including toilets, hotel bedroom doors, lift call buttons, top and bottom of stairs and wherever public safety is at risk.
The most simple technology used were based on the commission and reception of infrared rays which made it easier to detect obstacles as they reflect the infrared rays back objects within the radius of 3 to 4 metres can be detected (Archambault et al., 2007). Greater range was later obtained by the use of laser technology instead of infrared radiation. In some cases acoustic systems can be adapted to judge the location of the object by the varying loudness to inform users as to how far away the obstacle is.
These technologies can be termed ‘ancient' when compared with the latest advancements in the modern world. Various modern technologies are in the development or testing phase for users. The various technologies in the testing phase including GPS (Global Positioning System), GSM (Global System for Mobile Communications). WLAN (Wireless Local Area Network) and RFID (Radio Frequency Identification) and Bluetooth interface.
Experiments are being carried out which use these technologies separately or in combination with each other in order to provide the visually impaired user the most user-friendly and accurate directions to navigate across a given space.
The initial research was carried out using a handheld PDA (Personal Digital Assistant) device which used GPS technology to determine the location of the user and to further guide the user. But the GPS technology had its own drawbacks namely there was a location error, especially in dense urban regions especially in canyons which are created both in the urban or natural environment (Savidisa & Stephanidisa, 2005).
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Another major problem was that there is no GPS signal reception when the user is indoors (Krahe, 2007). In urban areas it was seen that triangulating the user with the help of GSM signals was much more accurate and when combined with the location calculated with the help of the GPS provided a reasonably good estimate of the real time location of the user (Savidisa & Stephanidisa, 2005).
The major drawback holding back the implementation of this amalgam of technology is that it uses too many signals and antennas meaning that too many resources are being used which are not readily available universally (Krahe, 2007). In the case of pinpointing the position of the person indoors the best available technologies are that of WLAN and Bluetooth interface.
It was determined with the help of detailed experiments that the location accuracy provided by Bluetooth network is generally more accurate than the location computed using a WLAN network (U10). But in the case of a controlled environment such as public offices or a museum the most advantageous and accurate technology for guiding the visually impaired user around the building is with the help of RFID technology (Foucher, 2007). RFID systems are composed of RFID microchip mounted on an object which is detected with the help of a RFID reader. The data derived from accurate RFID tag locations can be used to determine the location of the RFID reader (Krahe, 2007). For the sake of detailed explanation of this technology we take the example of a closed and controlled indoor environment with several points of interest typically like a museum. In this case the three major objectives that need to be achieved are (Foucher, 2007):
1) Ability to support and facilitate user movement and orientation.
2) Obstacle avoidance along any given path.
3) Access to information and description of items on display.
In this section we shall discuss in detail about the first two objectives to be achieved. The third objective will be discussed in detail when the access of the information by the visually impaired is evaluated in depth.
The RFID chip which is mounted on any given objects emits a signal of constant strength which means that depending upon the strength of the signal detected by the RFID detector the position of the user with respect to the objects around can be easily computed. This information coupled with the information collected with an electronic compass the position and the motion vector of the user can be determined accurately.
This information when coupled with the overall topology of the museum accurate navigation information can be given to the user via a vocal user interface (Keating et al., 2008). In this particular case study, a device emitting sound waves is sampled at 35Hz so that real time obstacles such as people around are detected and conveyed in real time. The device used here detects objects that are between 10 to 90cms from the source. The addition of vibrotactile feedback to supplement the voice commands was also experimented with varied response from the test group (Keating et al., 2008).
Another important factor that people use for efficient orientation and mobility skills is that they mentally map the spaces that they use regularly. Blind people do not have this information and as a consequence need to obtain this information with the help of other sensory channels for blind people to explore and learn new environments it tends to be a long process even with the help of special information - technology aids (Lahav &Mioduser, 2007) for the two types of aids that are available to help the visually challenged the types of active aids available have been discussed in detail.
The passive aids that are currently available include verbal descriptions, tactile maps, strip maps and physical models. But the current available passive aids have major limitations including enormous distance estimation, underestimation of component sizes, low information density on symbolic representation misunderstanding (Lahav &Mioduser, 2007).
In order to overcome these problems researchers from Israel have started working on a new virtual environment to construct a cognitive map to help the visually impaired to get a better understanding of the environment they are supposed to start working in.
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For this purpose they created a virtual environment which the user can interact with the help of a joy stick enhanced with sounds and alerts. This method proved to provide a better spatial knowledge of the environment than audio and haptic output (Lahav &Mioduser, 2007).
The major implication of this research is that, with the rapid availability of haptic devices the experience can be made easier with the help of the virtual environment which needs future research to be able to implement it as a viable technology (Lahav &Mioduser, 2007).
Information Access Aids:
The right to information is one of the pillars of social development which should apply to everyone but unfortunately this does not seem to be the case. The visually impaired face major obstacles in accessing information be it traditionally off books or of computing systems. In this context the notion of ‘computing platform' concerns a wide range of devices apart from traditional desktop computers including public-use terminals, phones, TV's car consoles and home appliances (Keating et al., 2008).
Information technology has become an integral part of the society owing mainly to the versatility of the internet which has evolved into a significant information and business tool. Its uses vary from acting as a simple source of information to buying tickets, performing bank transactions (Krahe, 2007).
To make sure people from all walks of life including the visually disabled the included in this IT revolution it is being ensured that both the requisite hardware and software for easy access of the web pages is developed and constantly improved.
To ensure that a visually disabled person is able to play an independent role as a citizen on equal footing as a normal person the following services must be available to them when appropriate (Savidisa & Stephanidisa, 2005)
1. Specific devices and aids.
2. Specially adapted material.
3. Material in accessible media such as Braille.
4. Optical aids.
5. Non - Optical and electronic aids.
6. Training and Family support.
7. Guidance to other institutions to ensure the accessibility and adaption of physical environments.
8. Training and guidance for external professionals, voluntary workers etc.
Braille which was invented in 1827 (Savidisa & Stephanidisa, 2005) by Louis Braille is probably the most commonly used method for reading by the blind. This had disadvantages of this language was that it was difficult to learn and occupied a lot of space. In the mid 1970s an electronic Braille, system of refreshable Braille was invented. This computer connectable refreshable Braille represented a major step towards internet accessible system (Savidisa & Stephanidisa, 2005). Until recently this was the only available method for visually challenged individuals to interact online. The current technologies that are being used by the visually challenged to obtain information from online sources include speech synthesis, scanners with tactile surfaces which have the ability to convert normal text to Braille and also the use of a haptic interface for representing scientific data. One of the major problems faced by the visually challenged person is the access of the World Wide Web (Hardwick et al., 1998). Even thought specialist browsers have been developed to aid the blind with the increase in the graphics and the increasing use of 3d images it is becoming increasingly difficult to present to the visually challenged user. In order to overcome this problem VRML (Virtual Reality Modeling Language) was introduced. In the recent times VRML combined with a haptic interface is being used to represent the online content for the visually impaired user (Hardwick et al., 1998).
Another important addition to this is the screen readers which read aloud the content present in the browser so that the visually impaired user can go through the content line by line. On a similar vein scanning devices are available which scan the page and correspondingly represents the page in Braille by protruding the surface points. The latest of these devices also have the additional option of using a loudspeaker to read out aloud the contents of the page (siftwire.com). In the current system scientific data is represented either using tactile imaging or haptic graphs. These systems themselves are not perfect and further research is being carried out to create systems that are practical for consumer use and also economically feasible to produce (Keating et al., 2008).
But on the other hand there are major arguments which doubt the effectiveness of these tools in delivering the requisite message to the user. This is exemplified by the screen readers that are being currently used where the visual recognition of a desktop object is reproduced in a non-visual form. However this representation is closer to the perspective of a sighted user rather than a visually disabled one which means specific interaction means are to be developed (Foucher, 2007). Hence it can be concluded that the basic components and arrangements need to be simplified such that their reproduction in the non-visual form convey the complete message to the user.
The problems faced by the visually challenged can be clearly perceived during the usage of modern learning tools such as interactive whiteboard. Modern education system has incorporated various tools such whiteboard and video conferencing to make learning more convenient and increase interaction among the student, teacher and various parties involved (Krahe, 2007). But there is always the fear that if the systems are not developed completely students with disabilities especially the ones that are visually impaired will be left behind. In order to overcome this difficulty generally a mediator is used. The mediator is generally responsible to add meaningful descriptions based how a normal user would interact with the system. This method is very effective and often overcomes the major obstacles that usually prevent the blind user to make complete use of the system (Krahe, 2007).
But in the particular case of a subject such as mathematics or any situation where equations are involved in becomes difficult for the visually disabled user to completely comprehend the subject as it is not possible to provide a rapid overview with the help of other communication channels namely audio and tactile (Archambault et al., 2007). This predicament makes it more difficult for blind people to comprehend mathematical concepts when compared with people with sight. The statistics show that the majority of the blind students do not do well in mathematical studies. In fact to date no totally blind student has been able to complete the higher level Leaving Certificate in the republic of Ireland (Archambault et al., 2007). This is a serious problem that the researchers are trying to overcome this serious problem by combing computer based MathML and Braille in order to represent the mathematical formulae for the blind in a working environment (Archambault et al., 2007).
The disabled, no matter the extent of disability or the walks of life need small or large additional privileges for them to be able to enjoy their full rights as a citizen and to participate in the economic, social and cultural development of the society on an equal standing with their fellow human beings. The society too recognises this need and is working towards this goal (Bonet-Borrás & Muñoz-Sevilla, 2007). A very good example is that of computer games for the visually disabled. Computer and video games have become an important part of child and youth culture especially in developed countries where the exposure to such games has shown significant development.
These games are now being used gradually by other groups of the population with the proportion of players growing in all age groups particularly among young adults (Archambault, Ossmann, et al., 2007). Special games are being developed in all the popular genres designed especially for the blind. This in turn seems to satisfy two major priorities. The first being that the children and the young adults from the disabled community do not feel left out but on the contrary feels a part of the society. Secondly the technological tools could potentially benefit them in their daily lives, at school or work meaning it is important that the children get used to using technology as early as possible. Apart from this the computer games can help enhance the psychomotor and cognitive development among disabled children (Archambault, Ossmann, et al., 2007).
The perspective Of A Visually Impaired Person:
In this particular case study the interaction of a blind college student with various kinds of technological devices either designed specifically to help visually impaired people or devices used by other users too. The major devices observed in this study included software used to read a website page aloud, a labeller that prints Braille and a talking wrist watch. The subject found the web site reader time consuming and kept getting lost and having to start over again. The labeller could perform personal tasks such as to put a Braille label on a CD case but couldn't be used to print the label for a gift to a sighted friend who could not read Braille. The talking wrist watch was useful to know the time but called too much attention every time the time was checked (Luce, 2009). This gives a perfect example of the products being developed for the visually disabled to use. The design is focused on the product itself but the end user is not given much consideration. This trend must end and the products being designed in the future must be designed such that the technology is adapted to suit the needs of the user and not the other way around.
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