Use of Mobile Phones by Individuals with Visual Impairments

Introduction

Mobile phones have been commercially available only for three decades but they are now indispensable for many. A great majority of mobile phones available in shops are designed with a preconception that the user will have good visual and auditory abilities. However, this is not the case for people with visual or auditory impairments. This article focuses on the issues of accessibility of mobile phones by individuals who are blind or visually impaired, assistive technologies, and design guidelines. For the sake of simplicity, the term individuals with visual impairments (IVI) will also include blind individuals.

Blindness is defined as visual acuity worse than 3/60, 1/20 (0.05), or 20/400 or no light perception (WHO, 2010). Here, visual acuity refers to the ability to see clearly, in standard Snellen notation. The first number in the fraction 3/60, for example, indicates that the distance at which the person can see clearly a specific print is 3 feet (0.9 m). The second number indicates that a normally sighted person can see the same print at 60 feet (18.3 m). A vision of 20/400 shows that the person is only able to see the largest letter (the big E in the Snellen chart) at 20 feet (6.1 m), whereas someone with normal vision can see the same letter E at 400 feet (121.9 m). Severe visual impairment is defined as visual acuity worse than 6/60, 1/10 (0.1), or 20/200 and equal or better than 3/60, 1/20 (0.05), or 20/400. Moderate visual impairment is defined as visual acuity worse than 6/18, 3/10 (0.3), or 20/70 and equal or better than 6/60, 1/10 (0.1), or 20/200 (Sardegna et al., 2002).

A critical issue in the use of mobile phones and any type of technology-driven product is accessibility. Accessibility is the usability of a device by the broadest possible population within the broadest possible range of environmental conditions. Accessibility with regard to telecommunication products such as mobile phones, portable computers, and pagers, implies that such products are readily obtainable for individuals with disabilities without added expense and that they do not pose extreme difficulty in such operations as input, device control, and output (Smith-Jackson, 2003). Many issues under accessibility can be grouped under the term usability. The five main features of usability were listed as (Nielsen, 1992; Smith-Jackson et al., 2003):

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  Ease of learning;

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  Efficiency;

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  Memorability (easy to remember procedures);

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  Low error rates;

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  Satisfaction.

Ideally, an IVI should be able to learn the use of a mobile phone easily and independently, use it efficiently, remember what to do easily in order to make or answer a call/write or receive a message, make zero or a small number of errors during operation, and be pleased by the product. If any of these conditions are not satisfied, the usability and accessibility of the mobile phone would be considered to be low by the user.

Mobile phones with low accessibility are commonly adapted by individuals with disabilities according to their own needs. Adoption in this context means both the acceptance of mobile phones and their transformation for easier use. Some adoption strategies include modifying a mobile phone, adapting to it, using multiple devices, and learning the use of the device offline (Kane et al., 2009).

While several adoption methods may be needed under different circumstances, researchers and industrial firms are constantly searching for means of improving the accessibility of mobile phones by compensating or alleviating the effects of visual impairment and other disabilities. Such solutions include products, devices, technical systems, and software and are known as assistive technologies (Johnsen et al., 2012).