Academic journal article Journal of Visual Impairment & Blindness

A Comparison of Subjects' Reading and Writing Performance and Preference While Using Various Portable Electronic Magnifiers

Academic journal article Journal of Visual Impairment & Blindness

A Comparison of Subjects' Reading and Writing Performance and Preference While Using Various Portable Electronic Magnifiers

Article excerpt

The ability to read print to help maintain independence and quality of life is a primary concern of people with visual impairments (Krieger, 1967; Lamoureux et al., 2007; Leat, Legge, & Bullimore, 1999; Nguyen, Weismann, & Trauzettel-Klosinski, 2009; Stelmack et al., 2008). One option for reading is a CCTV (closed-circuit television) or, using a more specific term, electronic magnifier. An electronic magnifier uses a camera to enlarge images onto a screen. It emerged as assistive technology in the early 1970s. Uslan, Shen, and Shragai (1996) provide a historical overview of the evolution and availability of electronic magnifiers. They report electronic magnifier systems "designed and built specifically for visually impaired people" from the 1950s to the early 1970s with Apollo Lasers and Visualtek bringing these products to the market in the early 1970s (Uslan, Shen, & Sharagai, 1996, p. 466).

Electronic magnifiers have the advantages of adjustable magnification, contrast enhancement, binocular viewing, and large screen size (Wolffsohn & Peterson, 2003). They have been shown to be an effective tool in improving reading performance (Jutai, Strong, & Russell-Minda, 2009), to be an important learning device for students (Peck, 1995), to increase reading rates (Lagrow, 1981), to extend reading duration (Goodrich, Kirby, Wagstaff, Oros, & McDevitt, 2004), and to provide lasting significant positive psychosocial impact (Huber, Jutai, Strong, & Plotkin, 2008). In the past, electronic magnifiers were only available as nonportable desktop electronic magnifiers. Portable electronic magnifiers are now readily available.

The aim of this study was to gain an understanding of preferences, and reading and writing performance of subjects with visual impairments using different portable electronic magnifiers. Performance was measured by assessing reading rates, writing speeds, and equivalent power used. Preferences were determined by having subjects rank ease of writing tasks with portable electronic magnifiers. This study assesses trends and provides information that practitioners may find useful as they demonstrate and prescribe portable electronic magnifiers.



Fourteen subjects were tested. The subjects' ages, ocular diagnosis, vision impairment, years of desktop electronic magnifier use, and education level are listed in Table 1. Subjects had no previous portable electronic magnifier experience, but they frequently used a desktop electronic magnifier for reading and writing. All subjects were employed at one of three agencies that serve people who are visually impaired (that is, those who are blind or have low vision). Subjects volunteered to participate, and all testing was done in their place of employment.

Portable electronic magnifiers

Eight portable electronic magnifiers were classified into large and small categories, based on screen size. Table 2 shows screen size and magnification range. Large portable electronic magnifiers had diagonal screen measurements of 14.61 to 17.78 centimeters and smaller ones had a measurement of 10.16 centimeters. Large portable electronic magnifiers were: Miniviewer and Olympia by Telesensory, Traveller by Optelec, and Assist Vision Slider by New Times. Small portable electronic magnifiers were: Compact by Optelec, Pico by Telesensory, Quicklook by Ash Technology, and PocketViewer by HumanWare.

Study design

Subjects read text and performed three different writing tasks with all eight portable electronic magnifiers and the desktop electronic magnifier they used daily. Testing was done over two sessions; each lasted 60 to 90 minutes. All features of each portable electronic magnifier were explained and demonstrated. The subjects were given an unlimited amount of time to practice. They used the level of magnification that was most comfortable for them, and it was not changed during testing. …

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