Assistive Technology: Vision Products

Original Editor - Robin Tacchetti Top Contributors - Robin Tacchetti, Naomi O'Reilly and Kim Jackson

Introduction

Globally, millions of people have vision loss or a visual impairment. Recent estimates that there are over 43 million blind people and 295 million people suffering from moderate-to-severe visual impairment with the majority of these individuals living in middle and low-income countries. Visual impairment can be classified by one's visual acuity:

• blind: vision below 20/400
• low vision: corrected vision is less than 20/70 and greater than or equal to 20/400

Visual impairment impacts quality of life in various ways such functional daily activities, indoor and outdoor movement, employment and independence. Additionally, dangerous situations can occur when these individuals encounter environments unfamiliar to them. These barriers individuals face daily can be overcome with the help of assistive technology. The wide range of vision assistive technology can be a simple low-tech device (large print book) to an expensive high-tech solution such as a Refreshable Braille Display. Recent advances in technology have expanded the digital assistive technology space.

Global Cooperation on Assistive Technology (GATE)

In 2014, the World Health Organization introduced the Global Cooperation on Assistive Technology (GATE). This initiative's aim is to address the significant gap between supply and demand for assistive technology for persons with disabilities in all countries. GATE published a list of the top 50 priority assistive products based on widespread need amongst the disabled. Of those 50 priority products, 16 of them are for people with visual impairments. These products are based on sound, smell, or sense of touch or vibration.

Different Types of AT (borges)

Optical:

Optical resources comprise devices that must be prescribed by specialized ophthalmologists and consist of one or more lenses, which are placed between the eye and the object to increase or adjust the visual image. In the category of optical resources for far vision, there are common eyeglasses, contact lenses, telescopes with adjustable focus or fixed focus. Among optical resources for close-up vision, there are manual, fixed, supportive magnifiers, regular glasses and magnifying glasses. These aids help to increase visual performance, especially in relation to reading and writing

Non-optical resources are those that improve visual function without the aid of lenses, are simple, useful, and transform materials and environments, providing better visual performance (Carvalho et al., 2005). In addition, they facilitate vision through environmental modifications, improving lighting conditions and increasing contrast; enlarge texts and printed images; and provide accessories to improve physical comfort (Romognolli & Ross, 2008). Among the non-optical aids, we should highlight the expansion of didactic books, notebook guidelines; suitable lighting; support for reading and writing; increased contrast with the use of stronger graffiti (pencil 6B); felt tip pens; use of very contrasting colors such as black ink on white paper, or white or yellow chalk to increase contrast with the board background; typescope (writing guide); portable lamps and so on

Electronic resources, in turn, allow people with low vision to have access to printed materials that optical magnifying glasses are unable to magnify enough to allow reading. They can magnify images up to 66 times without any distortion, as well as changing colors and contrasts to meet the diverse needs of each visually impaired person. Among the electronic resources, we highlight: Closed-Circuit Television (CCTV), electronic magnifying glass, scanners and autonomous text readers and video magnifiers.

Information and Communication Technology (ICT) resources are important tools for people with low vision and work through visual, sound and tactile interfaces or by combining them. The main device of this category is the computer, which, through software and resources, allows to meet the needs of each person with regard to magnification, contrast, text editing and sound support. The most commonly used resources by people with low vision, through the computer, are the screen magnifier software, which allows access to computers, acting as a virtual magnifying glass. Another option is the screen readers, which transmit the information contained on the computer screen through voice synthesizer

Smart Phone

Many smart digital assistive technologies based on electronic information, communication technology for visual impairment have been gaining a lot of importance across the world in recent times [7, 8]. Such smart assistive technologies have many accessible features and accessible applications for persons with disabilitie. With ongoing advance in smartphone technologies, it is becoming even more feasible for the person with visual impairment to rely on mobile technology in understanding their immediate surrounding, and to access huge amounts information that can improve their level of independent functioning, movement, social inclusion, participation, educational activities, and finally helps in improving the quality of life. large number of accessible built-in features have been developed specifically for people with blindness and visual impairment. ost widely used built-in accessible feature as screen readers are TalkBack for Android (Figure 4) and VoiceOver for Apple iOS (Figure 5) among people with visual impairment [17]. The Talback feature allows the user to easily identify the content or applications icons on the smartphones’ screen with a verbally speak words or voice from the device upon touching with fingers on the icons. By simply placing a finger on the icons, the smartphone will read aloud what icon is underneath the finger. Similarly, VoiceOver provides voice feedback aloud what appear on the smartphones’ screen, so iOS operating smartphone can be used without the need of visual function. A visually disabled individual can slide around on the screen with finger until the desired icons is located.

or a person with a low vision, the zoom magnification feature helps to magnify the entire screen to the required level of individual’s choice. Invert colors allows to change the white text on a black background, and vice versa or blue text on a yellow backgr (SENJAM SMARTPHONE ARTRICLE)- can use table feature insread

References 

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