Computer and World Wide Web Accessibility by Visually Disabled Patients: Problems and Solutions

SURVEY OF OPHTHALMOLOGY VOLUME 50 • NUMBER 4 • JULY–AUGUST 2005

PUBLIC HEALTH AND THE EYEJOHANNA SEDDON AND DONALD FONG, EDITORS

Computer and World Wide Web Accessibility byVisually Disabled Patients: Problems and SolutionsMichael F. Chiang, MD,1,2 Roy G. Cole, OD,4 Suhit Gupta,5 Gail E. Kaiser, PhD,5

and Justin B. Starren, MD2,3

1Departments of Ophthalmology; 2Biomedical Informatics, and 3Radiology, Columbia University College of Physicians andSurgeons; 4The Jewish Guild for the Blind; and the 5Department of Computer Science, Columbia University School ofEngineering and Applied Science, New York, New York, USA

Abstract. Rapidadvances in information technologyhave dramatically transformedtheworld duringthepast several decades. Access to computers and the World Wide Web is increasingly required for educationand employment, as well as for many activities of daily living. Although these changes have improvedsociety in many respects, they present an obstacle for visually disabled patients who may have significantdifficulty processing the visual cues presented by modern graphical user interfaces. This article reviewsthe specific barriers to computer and Web access faced by visually disabled patients, describes clinicalevaluation methods, summarizes traditional low vision methods as well as newer assistive computertechnologies for universal accessibility, and discusses emerging technologies and future directions inthis area. (Surv Ophthalmol 50:394–405, 2005. � 2005 Elsevier Inc. All rights reserved.)

Key words. access to information • biomedical technology • blindness • Internet • lowvision • medical informatics • user-computer interface • vision disorders • visual acuity

IntroductionRapid innovations in computer and communica-

tion technology have dramatically transformed theindustrialized world during the past several decades.A 2002 Harris Poll estimated that 66% of adult Ameri-cans regularly use the Internet, an increase of nearly700% since 1995. This is significantly higher than therate of growth of the telephone, automobile, radio,or television [Taylor H, Harris Poll #18, http://www.harrisinteractive.com/harris_poll/index.asp?PID=295, accessed 5/10/03]. The ongoing expan-sion of technology is providing unprecedented op-portunities for people to communicate and exchangeinformation with others around the world. But at

39

� 2005 by Elsevier Inc.All rights reserved.

the same time, those without the skills or resources toaccess information tools such as the World Wide Webwill be at a severe disadvantage in educational andemployment situations [Gunderson J, World WideWeb accessibility to people with disabilities: a usabilityperspective, http://www.staff.uiuc.edu/∼jongund/access-overview.html, accessed 3/5/03]. This divisionhas the potential to enlarge the existing economicand cultural gaps between the “haves” and “have-nots” in our society, and threatens to create majordifficulties for visually disabled patients. An im-portant challenge will be to ensure that visually disa-bled patients have mechanisms for universal accessto these emerging technologies.1

40039-6257/05/$–see front matter

doi:10.1016/j.survophthal.2005.04.004

COMPUTER ACCESSIBILITY FOR THE VISUALLY DISABLED 395

From another perspective, the problem of com-puter and Web accessibility is becoming increasinglysignificant because the prevalence of visual loss isrising. Patients 65 years of age and older have agreater prevalence of low vision than any other agegroup,38 and it is estimated that the number of Ameri-cans over the age of 65 will double between 2000 and2040.20,32 In 1997, the United States Census Bureaufound that there were 7.7 million adults with “non-severe visual limitation,” which was defined as a self-reported or proxy-reported “difficulty with seeingwords and letters, even with eyeglasses.” The CensusBureau similarly determined that there were 1.8 mil-lion American adults with “severe visual limitation,”defined as the “inability to see words and letters, evenwith eyeglasses” [Bureau of the Census, Survey ofincome and program participation, http://www.cen-sus.gov/hhes/www/disable/dissipp.html, accessed3/5/03]. In general, patients with even minimalvisual impairment are likely to encounter problems ineveryday life. For example, people with visual acuityworse than 20/40 cannot obtain an unrestricted driv-er’s license in most states, and may require assistivedevices such as magnifiers for reading.35 In this arti-cle, we will use the term “mild visual disability” torefer to patients who have decreased best correctedvisual acuity that causes difficulty with reading, andthe term “severe visual disability” to refer to thosewith no useful reading vision to support computeruse.

Well-known low vision aids, such as hand magnifi-ers, stand magnifiers, loupes, closed- circuit televisionsystems, and optical character recognition systems,are suitable for reading printed text.13,25 However,these traditional devices are often less effective athelping visually disabled users adapt to the uniquedata input and data display requirements of moderncomputer user interfaces. In recent years, a numberof new “assistive technologies” have emerged tofacilitate computer and Web accessibility by visuallyimpaired or blind patients. Given the increasing prev-alence of visual disability, as well as the growingimpact of information technology in contemporarysociety, eye care providers will need to become famil-iar with the characteristics and applications of theseassistive computer technologies.

The objectives of this article are to review the ex-isting literature about specific difficulties faced byvisually disabled patients while using computers, tosummarize international commitments toward uni-versal computer and Web accessibility, to describeclinical evaluation methods, to survey traditional lowvision methods as well as newer assistive technologiesfor accessibility, and to discuss future directions inthis area. Many assistive technologies are available,and this article will focus on those that are most

useful for modern computing applications such asgraphical user interface (GUI) manipulation andWorld Wide Web browsing. Some of these assistivetechnologies are suitable for users with severe as wellas mild visual disabilities, but the differing require-ments of these two groups will be highlightedwhere appropriate.

Problems With Computer and World WideWeb Use by Visually Disabled Patients

FUNDAMENTALS OF THE WORLD WIDE WEB

In the 1960s, the Internet began as the ARPANET,a networking project started by the United StatesDepartment of Defense to allow researchers at institu-tions across the country to communicate with eachother.30 In addition to information sharing, a majorgoal of the Internet founders was network supportfor distributed social interactions.28 Since that time,the Internet has evolved into a complex informationnetwork often considered synonymous with theWorld Wide Web. Web documents are identified bya unique Uniform Resource Locator (URL) address,and are based on the notion of “hypertext,” in whichcertain words and phrases are annotated by “links”that connect to another location in the same or adifferent document. Web pages are hosted on com-puters known as “servers,” and are accessed by usersfrom other computers through programs known as“browsers.” The Web became accessible to the gen-eral public following the 1993 release of the user-friendly graphical Mosaic browser, which led to thedevelopment of commercial applications and a userbase of several million people by the next year [Na-tional Center for Supercomputer Applications, NSFinitiative leads to NCSA Mosaic and e-commerce,http://www.ncsa.uiuc.edu/Divisions/PublicAffairs/MosaicHistory/impact.html, accessed 10/20/03].

In 1994, the international World Wide Web Con-sortium (W3C) was founded to organize and establishstandards for the Web. These W3C standards allowarbitrary individuals and organizations to developtheir own servers, browsers, and hypertext contentindependently, which will work together and be uni-versally available. One such standard is HypertextMarkup Language (HTML), the notation that Webpages are traditionally written in, allowing program-mers to specify the look and feel of a document[World Wide Web Consortium, Hypertext MarkupLanguage homepage, http://www.w3c.org/MarkUp,accessed 10/20/03]. Overall, the Web has evolvedrapidly in recent years, providing the public withaccess to vast stores of information. This creates twopotential difficulties for visually impaired patients.First, hypertext Web documents are nonlinear,allowing users to link quickly to other pages that may

396 Surv Ophthalmol 50 (4) July–August 2005 CHIANG ET AL

have a completely different design and layout. Thismay cause confusion for those who cannot easilyfollow visual cues. Second, the Web now revolvesaround video, multimedia, real-time collaboration,and interactive documents, all of which are heavilyvisually based.

TEXT-BASED AND GRAPHICAL USER INTERFACES

The vast majority of early computer systems con-tained pure text-based user interfaces, because limita-tions in computing speed made complex graphicalinterfaces impractical. Patients with mild visual disa-bilities were often able to access these early systemsusing traditional low vision mechanisms such as mag-nifying spectacles or large-screen monitors.5 In addi-tion, it was relatively straightforward for users withsevere visual disabilities to interact with these earlymachines, using keyboard input and voice output ofscreen contents, because the information was com-pletely text-based and therefore easy to access in tele-type mode.4 However, because of increased computerprocessing power since that time, GUIs with “point-and-click” interactions have largely replaced the old-fashioned text interfaces. Modern Web navigationusing browsers, such as Internet Explorer and MozillaFirefox, is heavily based on these graphical interfaces,which are intended to be intuitive, easy to remember,and relatively error-free. Basic graphical “widgets”such as icons, pushbuttons, pull-down menus, andcheckboxes are recognizable even by casual com-puter users as convenient mechanisms for data inputand output (Fig. 1). This is because information is

conveyed by reading textual labels, as well as by visual-izing their relationship with adjacent graphical fea-tures. Although GUIs are widely regarded as a majoradvance in human–computer interaction, their heavydependence on visual cues for input and output pres-ents a significant problem for visually disabled pa-tients.24,34 In this respect, growth of the Internetlargely occurred without consideration for the specialneeds of disabled users.27

PREVIOUS STUDIES INVOLVING COMPUTERUSE BY VISUALLY DISABLED PATIENTS

Although a large body of ophthalmic literature hasexamined the overall impact of visual disability onfunctional status and quality of life,7,25,31 few pub-lished studies have explicitly investigated the abilityof visually disabled patients to perform computer andWeb-based tasks.23,32,33 Uncorrectable visual loss mayof course be manifested in several different ways,depending on the underlying etiology. Deficits invisual function parameters such as visual acuity,central visual field, peripheral visual field, contrastsensitivity, and color vision are likely to have differingeffects on the ability of patients to use graphical inter-faces for computer input and output. However, verylittle research has attempted to link the specific pro-file of visual impairment with computer taskperformance.21,22,32

The most comprehensive and systematic evalua-tions to date were performed by Scott et al, who ex-amined the ability of 18 visually disabled patients

Fig. 1. Common computer interface “widgets” contain graphical cues that are easily recognizable by sighted users, butwhich may cause significant accessibility problems for sight-impaired patients. This is because information is conveyednot only by reading textual labels, but also by visualizing their relationship with adjacent graphical features. Tabbed folders(1) are used to graphically organize and display information output. Checkboxes (2), slider bars (3), and buttons (4)are used for data entry. Menu bars (5) are used for data organization, input, and output. Icons (6) are a symbolicrepresentation of information for data input and output, and rely on users’ ability to identify images. Navigation bars(7) and hypertext (8) are used to organize data display on Web pages. In each case, users must be able to recognize textand images, interpret proper mechanism for human-computer interaction, and use a data input tool such as mouseor keyboard.


with age-related macular degeneration (AMD) tomanipulate and interact with computer graphicaluser interface features. The findings from those stud-ies were analyzed in two ways: 1) In terms of graphicalinterface features, smaller icon size and larger iconset size were significantly associated with lower com-puter task accuracy, whereas smaller icon size wassignificantly associated with slower task completionspeed;33 and 2) In terms of visual function parame-ters, decreased visual acuity, decreased contrast sensi-tivity, and decreased color vision were significantlyassociated with lower computer task accuracy,whereas decreased visual acuity and decreased colorvision were significantly associated with lower taskcompletion speed.32

STATISTICS

The American Foundation for the Blind, in collab-oration with the United States Bureau of the Census,has collected extensive statistics regarding Internetaccess and regular computer use by visually disabledpatients.2 Based on these data, there are four notabletrends.16 First, people with visual limitations aremuch less likely to use a computer regularly or tohave regular access to the Internet, compared topeople without visual disabilities (Table 1). Second,individuals with severe visual disability have lowerrates of Internet access than those with mild visualdisability (13% compared to 23%). Similarly, individ-uals with severe visual disability have lower rates ofregular computer use than those with mild disability(7% compared to 15%). Third, many patients withvisual disabilities are elderly people who suffer fromadditional impairments such as hearing loss or physi-cal limitations. As shown in Table 2, adults whoseonly disability is visual loss have higher rates of In-ternet access than those with visual disability accom-panied by one or more other impairments (53%compared to 28%). Fourth, the rates of Internetaccess and regular computer use may be affectednot only by visual disability, but also by the factor ofemployment. Among employed people aged 25–49,64% of those with no disabilities had Internet access,compared to a similar number (54%) of those withvisual disabilities.

Taken together, these statistics certainly suggestthe existence of significant disparities in computerand Internet access among patients with visual dis-ability. At the same time, the statistics about computeruse by those with isolated visual disability, and bythose who are employed, suggest that computer ac-cessibility is feasible by patients with visual impair-ments. However, it is difficult to draw definitiveconclusions because the above associations are notnormalized for variables such as education andincome status.16

ACCESSIBILITY LEGISLATION IN THEUNITED STATES

The Americans with Disabilities Act (ADA) of 1990includes several provisions that required employersto provide “reasonable accommodation” and mecha-nisms for “effective communication” to workers withdisabilities [United States Department of Justice,Americans with Disabilities Act home page, http://www.usdoj.gov/crt/ada/adahom1.htm, accessed 3/5/03]. This law is applicable to the entire nation, notonly to entities that receive federal funds, and wasoriginally focused on areas such as employment,public accommodations, and telecommunication ser-vices. However, the subsequent growth of the In-ternet for communication in educational and worksettings has now broadened the ADA’s scope to re-quire “electronic curb cuts and ramps” that allowdisabled users to access computers and the WorldWide Web.3,17,29

Two other significant pieces of legislation per-taining to the accessibility of electronic and informa-tion technology are Sections 508 and 504 of theFederal Rehabilitation Act of 1973. Section 508requires that all electronic and information technol-ogy that is developed, procured, or used by federalagencies must be accessible to people with disabilities[United States General Services Administration, Sec-tion 508, http://www.section508.gov, accessed 2/27/03]. Because this law is based on the U.S. AccessBoard’s Electronic and Information Technology Ac-cessibility Standards, which are in turn based on theWorld Wide Web Consortium’s Web Content Accessi-bility Guidelines (see Summary), it has become an

TABLE 1

Rates of Internet Access and Regular Computer Use Among Visually Impairedand Non-visually Impaired Users, Aged 15 and Older

Visual Impairment* No Visual Impairment

Internet Access Regular Computer Use Internet Access Regular Computer Use

21% 13% 57% 51%Total number: 7,326,000 Total number: 166,108,000

* Visual impairment defined as “difficulty with seeing words and letters, even with eyeglasses.”


TABLE 2

Rates of Interest Access and Regular Computer Use Among Patients with Isolated VisualImpairment and Multiple Physical Impairments, Aged 15–64

Only Visual Impairment* Multiple Impairment

Internet Access Regular Computer Use Internet Access Regular Computer Use

53% 42% 28% 18%Total number: 919,000 Total number: 2,680,000

* Visual impairment defined as “difficulty with seeing words and letters, even with eyeglasses.”Note that total number of patients is different from Table 1 because of different age ranges.

important legal reference for Web accessibility.36 Al-though Section 508 applies only to direct purchasesby the federal government and not to purchasesmade by entities receiving federal funding, it mayhave an important impact on the design of computersystems for universal accessibility because of thebuying power of the United States government.26

In contrast, Section 504 has a more general scope,requiring that all educational programs receivingfederal funds must be accessible to all studentswith disabilities [United States Department ofLabor, Section 504, http://www.dol.gov/oasam/regs/statutes/sec504.htm, accessed 3/7/03]. Together,these laws represent a large-scale, national commit-ment to include people with sensory, physical, or cog-nitive disabilities in all facets of life.17,39

Traditional Low Vision SolutionsGENERAL FACTORS REGARDING ACCESSIBILITY

The goal of most traditional low vision approachestoward computer accessibility is to provide sight-enhancement rehabilitation mechanisms that max-imize the useful remaining vision. This includes threemain components: standard refractive care, special-ized care for patients with reduced vision, and specificadvice on the use of computers.

Standard refractive care places the best focusedimage on the retina. Specialized care for patientswith reduced vision includes the determination andcompensation for magnification and lighting needs.Traditional hand-held magnifying devices are gener-ally not optimal for computer use because of theunique data display and entry requirements of graph-ical user interfaces. However, many visually disabledpatients will require magnification, which may beprovided by high reading adds with concomitantcloser working distance, as discussed below (LowVision Approaches Based on Characteristics of VisualLoss). Lens design is an important factor, with eitherfull-field computer lenses or bifocal segments largeenough to see most of the screen. Increased conver-gence demands caused by reduced working distancemay require base-in prism to preserve binocular

vision. Font enlargement and screen magnificationsoftware programs are often very useful, as discussedbelow (Assistive Technology Solutions). Lightingshould be sufficient; at the same time, lights thatcause glare reflecting from the computer screenshould be moved.

Specific advice on the use of computers involvesergonomic factors and screen enhancement capabili-ties that the patient already has access to. Severalrecommendations may be given to visually disabledpatients: 1) Computer monitors should be posi-tioned directly in front, and slightly lower than, eyelevel; 2) If typing from a page, a stand should be usedto support the page to one side of the monitor,at the same distance as the monitor; 3) If a bifocalsegment is used, it should be positioned so that un-usual head position or neck flexion is not required;and 4) Text font size may be increased in softwareapplications for easier readability. Similarly, reduc-tion of screen resolution will increase the size ofmaterial on the computer screen, although this mayrequire additional scrolling to see the entire page.

LOW VISION APPROACHES BASED ONCHARACTERISTICS OF VISUAL LOSS

Clinical evaluation of visual function parameterswill guide the decision as to the most appropriatemechanisms for supporting computer accessibility.Best corrected visual acuity is used to predict themagnification required for reading. This will deter-mine the required reading add, or the appropriatecombination of screen magnification and higher add.As a general rule, visual acuity of approximately 20/50 will allow patients to read a standard computerscreen, although this can vary depending on thescreen size and resolution setting. Based on thatrule, a patient with 20/200 visual acuity would needa magnification of 4× (200/50). This magnificationmay be provided by moving the monitor to a distance4× closer, and then by prescribing an appropriatereading add for that distance. The reading add mayquickly be determined by taking the product of therequired magnification and the standard add of


�2.50 D (e.g., (4×)(�2.50 D) � �10.00 D). Alterna-tively, this may be accomplished by combining screenmagnification with a reading add. For example,enlarging the letters 2× and using a 2× magnificationadd (i.e., �5.00 D) will give the same results as usinga �10.00-D add alone. Increased convergence de-mands caused by shortened working distance mayrequire base-in prism in lenses to preserve binocu-lar vision.

Visual fields may be plotted with perimetry orAmsler Grid. This will provide guidance to patientsregarding compensatory approaches. For example,patients with left homonymous hemianopia shouldbe instructed how to return back to the beginningof each line of text, whereas those with right homony-mous hemianopia must be instructed to go to theend of each line. Interestingly, patients withdecreased peripheral visual field may benefit fromreduction in screen size, rather than magnification,assuming that their visual acuity is adequate. Withreduced contrast sensitivity, magnification alone maynot be sufficient to support accessibility. In that situa-tion, procedures to enhance screen contrast maybe beneficial. Many computer operating systems havebuilt-in screen enhancement capabilities that maybe used to enlarge the screen, and to enhance thecontrast of the material being viewed (Fig. 2).

Overall, the optimal low vision strategy will dependon the type and severity of visual disability. A classifi-cation system based on the type of visual field loss hasbeen developed by Faye to categorize sight-impairedpatients.13 Although all patients should fit into oneor more of these categories, management decisionscan of course be made only after assessment and

evaluation of an individual’s specific needs and ca-pacities. These general guidelines regarding visualperformance are the following:13 1) Patients withoverall blur, glare, or loss of contrast, but withoutcentral scotoma, should initially try magnification,appropriate lighting, and contrast enhancement; 2)Patients with central scotoma should try magnifica-tion, as well as contrast enhancement; and 3) Patientswith constricted peripheral visual field, but with rela-tively preserved visual acuity, may try reducing com-puter screen size. Alternatively, they may need tobecome good at scanning the computer screen.

Assistive Technology SolutionsGOALS AND CHALLENGES FOR ASSISTIVETECHNOLOGY

The overall goal of visual assistive technology isto provide equivalent, sight-enhancement or sight-substitution rehabilitation mechanisms for computerand Web access that are appropriate for the level ofdisability. For patients with severe visual disability, thisrequires non-visual alternatives for traditionally visualtasks such as reading text, selecting from menus, re-sponding to system prompts, analyzing tables, andnavigating between different parts of Web sites. Ingeneral, this is accomplished by translating the visualscreen display into auditory output (e.g., screen read-ing software with speech synthesizers), tactile output(e.g., Braille display that echoes the screen display),or a combination of the two modalities.6 For userswith mild visual disability, more conservative adapta-tions such as screen magnification may also beappropriate.

Fig. 2. Screen views to demonstrate output produced by built-in accessibility options, which are available with manymodern computer operating systems such as Microsoft Windows. Image (A) is normal screen view. Image (B) is the samescreen viewed with “high contrast” and “enlarged text” options, to facilitate accessibility by some visually disabled patients.


As discussed above, the problem of Web accessfor visually disabled patients is particularly difficultbecause the Web navigation paradigm is depen-dent on graphical interfaces with visual cues. Specialchallenges for assistive technology devices includetranslation of complex mathematical and scientificnotation into computer-readable formats; interpreta-tion and display of images and digital videos; efficientnavigation and interpretation of Web-based tables;and entry of data using Web-based text boxes andforms.29 Successful solutions to these problems willrequire not only that assistive technologies arewell-designed, but also that Web site content andlayout are organized to promote accessibility (seeSummary).

SCREEN MAGNIFIERS

A straightforward adaptive strategy for many par-tially sighted patients is simply to enlarge the com-puter screen. In the past, this was often done usinglarge-screen monitors. Recently, screen magnifiersoftware applications have become more popular.Screen magnifiers run as background tasks, and areideally compatible with all other commercial soft-ware products such as word processors, spreadsheets,and Web browsers. Typical screen magnifiers providethe capability of enlarging both text and graphicsover a wide range of levels. The user generally deter-mines whether the full screen is magnified, orwhether only the portion of the screen that tracksthe cursor or menu bar activity is magnified (Fig. 3).Most of these products use image-smoothing algo-rithms to produce clear graphics and text even atlarge magnifications, and some products include spe-cial functionalities such as the ability to automaticallyscan and review an entire screen. Popular commer-cial screen magnifiers are currently manufactured byAi Squared (ZoomText; Manchester, VT) andTieman UK (Lunar; Nottingham, UK). Althoughscreen magnifiers are popular among users with mildvisual disability, they provide little benefit for thosewith severe visual disability.

BRAILLE DISPLAYS

Electronic Braille displays are typically connectedto a keyboard and produce refreshable, line-by-linedisplays of text output (Fig. 4). These devices consistof numerous arrays of movable pins that are con-nected to solenoids or piezoelectric outputs. De-pending on the specific electrical signal received fromthe source computer system, the pins are raised orlowered to generate Braille characters. Computerdata input may be performed using standard key-boards, although special Braille keyboards are alsoavailable to complement Braille displays. In general,

Braille output displays have been useful for allowingpatients with severe visual disability to perform accu-rate proofreading and review of computer screenlayouts.41 Of course, these are purely text-based andtherefore less helpful when used alone for Web-based and other graphical interfaces. Their wide-spread application has been further limitedbecause of the relatively small number of completelyblind patients who regularly use Braille. Accordingto recent statistics from the American Foundationfor the Blind, there were 55,200 legally blind chil-dren in the United States in 1998–1999, of whom only5,500 used Braille as their primary reading medium.2

SCREEN READERS

The purpose of screen reading programs is totranslate text and graphical displays into auditoryoutput. This is performed using software synthesizerprograms to drive sound cards that are built in tomost computer systems, or using external hardwarespeech synthesizers. As in the case of screen magnifi-ers, screen readers are background software applica-tions that operate transparently to word processors,spreadsheets, Web browsers, and other commercialsoftware packages.

Screen readers have become a popular technologyamong patients with severe or complete visual loss,who may navigate the screen using keystrokes whilethe assistive software announces the word or line atthe cursor location.41 Most commercially availablescreen readers will automatically announce menubars and pop-up windows, and they will use standardprotocols and voices to identify icons, radio buttons,text boxes, and other common graphical user inter-face widgets. When used with Web browsers, screenreaders will generally announce text and graphiccontent, and will note the presence of hyperlinks. Inaddition, they include specific features to orient Webusers by reading information about navigation barcontents, table column and row headings, andother page layout and navigation details.

Popular screen reading programs are published byFreedom Scientific (JAWS; St. Petersburg, FL), ALVAAccess Group (outSPOKEN; Oakland, CA), and Dol-phin Computer Access (Hal; San Mateo, CA).Although most screen readers work well with Webbrowsers, several software packages that have beenexclusively designed to provide speech access for Webnavigation and electronic mail purposes (e.g., IBMHome Page Reader; White Plains, NY) are also avail-able. A simple screen reading program, known asNarrator, is available with the Microsoft XP operatingsystem (Microsoft Corporation; Redmond, WA).While screen readers may be effective as an isolatedtechnology to support data display and entry, they


Fig. 3. Simulated screen view produced by screen magnifier used in “vertical split mode.” Left side of computer screenis normal size, and orients visually disabled patient to overall screen layout and organization. Right side of screen isenlarged, in the area where patient is working (note position of cursor). Amount of magnification may be variablyadjusted, allowing some visually disabled patients to read details on screen.

are frequently used in combination with other de-vices such as Braille displays or screen magnifiers.6,41

Emerging Technologies and FutureDirections

MOTIVATION

Because computer-based technologies are evolvingrapidly, assistive technologies and other tools to im-prove computer and Web accessibility are also ad-vancing quickly to keep pace.6,29,36 For those reasons,physicians and others who care for visually impairedpatients should become aware of these new tools asthey emerge.

DESIGN GUIDELINES FOR UNIVERSALWEB ACCESSIBILITY

Legislative requirements, low vision solutions, andassistive technologies are not sufficient to allowWorld Wide Web accessibility by visually disabled pa-tients. Ultimately, these adaptations are only usefulfor reading Web content to the extent that Web sitesare developed with the special requirements andneeds of disabled users in mind. For this reason, theW3C has undertaken a broad initiative to ensure thatWeb programs are written to be maximally accessibleby disabled patients. The W3C publishes a series of

Web Content Accessibility Guidelines, which havebecome an international standard for creating uni-versally accessible Web-based products.10 For exam-ple, one design guideline states that “alternative textequivalents” must be available for all non-text ele-ments such as images or video animations (Fig. 5).These text equivalents should describe the contentthat the image was intended to convey, so that screenreaders may output the auditory information. How-ever, text equivalents are often omitted by Web au-thors, making information inaccessible to visuallydisabled users.9,37

Similarly, W3C has begun to create standardizedguidelines for the speech rendering of Web docu-ments [World Wide Web Consortium, CSS3 SpeechModule, http://www.w3.org/TR/2003/WD-css3-speech-20030514/, accessed 5/30/03]. This willallow Web designers to specify parameters such asthe volume, inflection, and rate of speech, such thatauditory information may be conveyed optimally tovisually disabled patients using screen readers.

Although these design guidelines were originallydirected toward disabled users, they are likely to ben-efit a much larger population of users, such as thosewith slower Internet connection speeds or non-tradi-tional Web browsers (e.g., mobile computingdevices).36,40


Fig. 4. Electronic Braille display for reading text output. Movable pins are raised or lowered based on electrical signalsto generate characters on Braille display. Data input may be performed using standard keyboard or special Braille keyboard.

IMPROVED COMPUTER INTERACTION DEVICESFOR ACCESSIBILITY

A hallmark of the GUIs used by most modern op-erating systems, software packages, and Web-basedapplications is that they rely on a mouse or a similarpointing device. Although patients with mild visualdisability may still find that using a pointing device ismore efficient than attempting to navigate graphicalinterfaces using keystrokes with a screen reader,problems such as decreased visual acuity and re-stricted visual field present major challenges forpointing devices.15 Examples of these experimentaldevices include a “target mouse” that provides audi-tory assistive feedback when the pointer enters orexits a target region, high-contrast “roll-over” buttonsthat make the target entrance more obvious by usingredundant visual cues, and color adjustments to im-prove the visibility of the pointer.15,24

CONTENT EXTRACTION FROM WEB PAGES

Web documents are often cluttered with featuressuch as pop-up advertisements, banners, and super-fluous links that may distract users from the actualcontent of the page. These cluttering features maybe particularly disorienting for low vision patients,particularly because assistive technologies such asscreen readers are generally unable to automaticallyremove these extraneous materials and are thereforeforced to simply read them out. Gupta et al havedeveloped a software tool for content extraction fromWeb pages.18 Documents that have been filtered by

this tool may be input to screen readers or otherassistive technologies, potentially allowing visuallydisabled users to understand the essential content ofWeb pages more efficiently.18 Although methodolo-gies for effective content extraction are still devel-oping, this concept may play an important role forsupporting accessibility in the future.8,14

VOICE RECOGNITION

Automated voice-recognition technology contin-ues to improve, and is being used in diverse applica-tions such as automated dictation, telephone systems,voice email, and mobile computing devices. Emerg-ing voice-based Web browsing systems offer thepotential for voice-driven navigation and telephone-based Web access, and provide opportunities for im-proved data input by visually disabled patients11

[World Wide Web Consortium, W3C home page,http://www.w3c.org, accessed 2/15/03]. Well-known existing products are manufactured bySpeech Technology (Dragon NaturallySpeaking;Wellington, FL) and IBM (ViaVoice; White Plains,NY). When used for medical applications, commer-cially available voice-recognition programs have beenfound to have transcription error rates between 7%and 15%.12 These programs have been shown to becost-effective in limited medical transcription studiesby pathologists and emergency room physicians.19,42

SummaryThe recent information technology revolution has

produced rapid social changes. Access to comput-ers and the Internet is increasingly required for edu-cation and employment, as well as for many activities


Fig. 5. Equivalent alternatives to visual content on Web pages. (A) and (B) show the same Web document with embeddedtext equivalents to describe image contents, making it accessible to visually disabled users through auditory screen readingsoftware. (C) Shows a simulated view of the same Web image without text equivalents, making it completely inaccessibleto visually disabled users. Image courtesy of National Eye Institute, National Institutes of Health.

of daily living, and these factors are threatening towiden the existing digital divide in our society. Inmany ways, the rapid growth of the Internet did notaccount for the specific needs of low vision patients.Fortunately, legislative requirements and assistivetechnologies have recently emerged in support ofaccessibility. Physicians will need to understand theetiologies of these existing barriers to computer andWeb access by their patients, the significance of thisproblem, the potential solutions offered by a newfamily of assistive technologies, and the limitationsof these technologies.

Existing assistive devices are being used successfullyby some visually disabled patients, and are continuingto improve.5,6 However, important gaps in knowledgeremain. The unique assistive needs of patients withdiffering patterns of visual loss are not known.21,22

Systematic usability evaluations of existing assistivetechnologies in visually disabled patients have not

been performed. Furthermore, the cognitive strate-gies used by blind and partially sighted patients toorganize and process information during computerand Web navigation are not well-understood. Thesuccessful planning and execution of this researchwill require collaboration among physicians, com-puter scientists, medical informaticians, cognitive sci-entists, and policy makers.

Method of Literature SearchThe MEDLINE database and the Association for

Computing Machinery (ACM) digital library werequeried, without any date limitations. The followingsearch terms were used: vision disorders, blindness, lowvision, visual impairment, visual disability, medical in-formatics, Internet, World Wide Web, access to informa-tion, accessibility, assistive technology, user interface, and


voice recognition. Criteria for inclusion were the rele-vance, clinical importance, and scientific impor-tance of articles to the subject of this article. Articlescited in the reference lists of other articles werereviewed and included when considered appropriate.All articles with English abstracts were reviewed, butonly English-language articles were used for thisreport. Additional sources included relevant Websites, as well as reference materials provided by TheJewish Guild for the Blind, Lighthouse International,and the American Foundation for the Blind.

References1. Altman RB: Informatics in the care of patients: ten notable

challenges. West J Med 166:118–22, 19972. American Foundation for the Blind : Statistics and sources

for professionals. New York, American Foundation for theBlind, 2000

3. Blanck PD, Sandler LA: ADA Title III and the Internet:technology and civil rights. Ment Phys Disabil Law Rep 24:855–59, 2000

4. Boulton LM: A clinical evaluation of equipment which allowsthe partially sighted and blind to access computer-basedinformation. Aust NZ J Ophthalmol 17:87–93, 1989

5. Boulton LM: Computer hardware and software to assist thevisually impaired and blind. Aust NZ J Ophthalmol 21:7–14, 1993

6. Brown C: Assistive technology computers and personal withdisabilities. Commun ACM 35:36–45, 1992

7. Brown GC: Vision and quality-of-life. Trans Am OphthalmolSoc 97:473–511, 1999

8. Buyukkokten O, Garcia-Molina H, Paepcke A: Seeing thewhole in parts: text summarization for web browsing onhandheld devices, in Proceedings of the Tenth InternationalConference on World Wide Web. New York, ACM Press,2001, pp 652

9. Chiang MF, Starren J, et al: Evaluation of consumer healthwebsite accessibility by users with sensory and physical dis-abilities. Medinfo 11(pt2): 1128–32, 2004

10. Chisolm W, Vanderheiden G, Jacobs I: Web content accessi-bility guidelines 1.0. Interactions 8:35–54, 2001

11. Christian K, Kules B, Shneiderman B, Youssef A: A compari-son of voice controlled and mouse controlled web browsing,in Proceedings of the Fourth International ACM Conferenceon Assistive Technologies. New York, ACM Press, 2000, pp72–9

12. Devine EG, Gaehde SA, Curtis AC: Comparative evaluationof three continuous speech recognition software packagesin the generation of medical reports. J Am Med Inform Assoc7:462–8, 2000

13. Faye EE: Maintaining visual functions in the elderly. Bull NYAcad Med 60:987–93, 1984

14. Finn A, Kushmerick N, Smyth B: Fact or fiction: contentclassification for digital libraries, in Proceedings of theSecond DELOS Network of Excellence Workshop on Perso-nalisation and Recommender Systems in Digital Libraries.Sophia-Antipolis Cedex, France, ERCIM, 2001, pp 2–6

15. Fraser J, Gutwin C: A framework of assistive pointers for lowvision users, in Proceedings of the Fourth International ACMConference on Assistive Technologies. New York, ACM Press,2000, pp 9–16

16. Gerber E, Kirchner C, et al: Who’s surfing? Internet accessand computer use by visually impaired youths and adults.J Vis Impair Blind 95:176–81, 2001

17. Gunderson J: Americans with Disabilities Act (ADA): humancomputer interaction and people with disabilities, in Confer-ence Companion on Human Factors in Computing Systems.New York, ACM Press, 1994, pp 381–2

18. Gupta S, Kaiser G, Neistadt D, Grimm P: Adapting contentto mobile devices: DOM-based content extraction of HTMLdocuments, in Proceedings of Twelfth International Confer-ence on World Wide Web. New York: ACM Press, 2003, pp207–14

19. Henricks WH, Roumina K, Skilton BE, et al: The utility andcost effectiveness of voice recognition technology in surgicalpathology. Mod Pathol 15:565–71, 2002

20. Institute for Health and Aging, University of California, SanFrancisco : Chronic Care in America: A 21st Century Chal-lenge. Princeton, NJ: Robert Wood Johnson Foundation,1996

21. Jacko JA, Sears A: Designing interfaces for an overlooked usergroup: considering the visual profiles of partially sightedusers, in Proceedings of the Third International ACM Confer-ence on Assistive Technologies. New York, ACM Press, 1998,pp 75–7

22. Jacko JA, Dixon MA, Rosa RH, et al: Visual profiles: a criticalcomponent of universal access, in Proceedings of the SIGCHIConference on Human Factors in Computing Systems. NewYork, ACM Press, 1999, pp 330–7

23. Jacko JA, Barreto AB, Marmet GJ, et al: Low vision: The roleof visual acuity in the efficiency of cursor movement, inProceedings of the Fourth International ACM Conferenceon Assistive Technologies. New York, ACM Press, 2000, pp1–8

24. Kline RL, Glinert EP: Improving GUI accessibility for peoplewith low vision, in Proceedings of the SIGCHI Conference onHuman Factors in Computing Systems. New York, ACM Press,1995, pp 114–21

25. Kraut JA, McCabe CP: The problem of low vision, in AlbertDA, Jakobiec FA (eds): Principles and Practices of Ophthal-mology. Philadelphia, WB Saunders, 1993, ed 1, pp 3664–83

26. Ladner RE: Computer accessibility for federal workers withdisabilities: it’s the law. Commun ACM 32:952–6, 1989

27. Laux LF, McNally PR, Paciello MG, Vanderheiden GC: De-signing the World Wide Web for people with disabilities: auser centered design approach, in Proceedings of the SecondAnnual ACM Conference on Assistive Technologies. NewYork, ACM Press, 1996, pp 94–101

28. Licklider JCR, Clark W: On-line man computer communica-tion. Proc Spring Joint Computer Conf 21:113–28, 1962

29. Paciello MG: Web Accessibility for People with Disabilities.Lawrence, Kansas, CMP Books, 2000

30. Roberts LG: Multiple computer networks and inter-computercommunications, in Proceedings of the First ACM Sympo-sium on Operating System Principles. New York, ACM Press,1967, pp 3.1–3.6

31. Scott IU, Schein OD, West S, et al: Functional status andquality of life measurement among ophthalmic patients.Arch Ophthalmol 112:329–35, 1994

32. Scott IU, Feuer WJ, Jacko JA: Impact of visual function oncomputer task accuracy and reaction time in a cohort ofpatients with age-related macular degeneration. Am J Oph-thalmol 133:350–7, 2002

33. Scott IU, Feuer WJ, Jacko JA: Impact of graphical user inter-face screen features on computer task accuracy and speedin a cohort of patients with age-related macular degenera-tion. Am J Ophthalmol 134:857–62, 2002

34. Shneiderman B: Universal usability: pushing human-com-puter interaction research to empower every citizen.Commun ACM 43:84–91, 2000

35. Shoemaker JA: Vision Problems in the US: Prevalence ofAdult Vision Impairment and Age-Related eye Diseases inAmerica. Bethesda, MD: National Eye Institute, 2002

36. Sierkowski B: Achieving web accessibility, in Proceedings ofthe 30th annual ACM SIGUCCS Fall Conference on UserServices Conference. New York, ACM Press, 2002, pp 288–91

37. Sullivan T, Matson R. Barriers to use: usability and contentaccessibility on the web’s most popular sites, in Proceedingsof the Conference on Universal Usability. New York, ACMPress, 2000, pp 139–44

38. Tielsch JM, Sommer A, Witt K, et al: Blindness and visualimpairment in an American urban population: the BaltimoreEye Survey. Arch Ophthalmol 108:286–90, 1990


39. Turnbull SB: People with Disabilities and the National Infor-mation Infrastructure (NII), in The Information Infrastruc-ture: Reaching Society’s Goals Report of the InformationInfrastructure Task Force Committee on Applications andTechnology. Washington: U.S. Department of Commerce,Technology Administration, National Institute of Standardsand Technology, 1994

40. Vanderheiden G: Fundamental principles and priority settingfor universal usability, in Proceedings of the Conference onUniversal Usability. New York, ACM Press, 2000, pp 32–7

41. Votta M, Lloyd S: Introduction to Assistive Technology.New York: Lighthouse International, 2001

42. Zick RG, Olsen J: Voice recognition software versus a tradi-tional transcription service for physician charting in the ED.Am J Emerg Med 19:295–8, 2001

Supported by grant LM07079 from the National Library of Medi-cine (MFC), grant EY013972 from the National Eye Institute(MFC), grants CCR-0203876 and EIA-0071954 from the NationalScience Foundation (SG, GEK), Defense Advanced Research Proj-ect Agency Order K503 monitored by Air Force Research. Labora-tory F30602-00-2-0611 (SG, GEK), Microsoft Research, IBM, andResearch to Prevent Blindness. The authors reported no commer-cial, proprietary, or financial interest in any of the productsor concepts described in this article.

Reprint address: Michael F. Chiang, MD, Department of Oph-thalmology, Columbia University College of Physicians and Sur-geons, 635 West 165th Street, Box 92, New York, NY 10032. Email:[email protected].

Computer and World Wide Web Accessibility by Visually Disabled Patients: Problems and Solutions

Documents

Transcript of Computer and World Wide Web Accessibility by Visually Disabled Patients: Problems and Solutions