2000 Conference Proceedings

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"The Integration of Low Vision Aids and Other Assistive Devices in Educational and Vocational Settings"

Matthew H. Ater, Director
Assistive Technology

Krista M. Davis, O.D., Director
Low Vision Services

Columbia Lighthouse for the Blind
Washington, DC

New advances in technology are quickly changing the way people with low vision live, work and learn. Today, along with traditional and innovative low-tech devices, assistive technology software packages meet a variety of low vision needs. By combining the use of low-tech and high-tech products, people with low vision can more readily compete with their sighted peers in the home, work, and school environments. Although devices such as magnifiers, scanners, large-print software programs, closed circuit television (CCTVís) and other electronic or video magnifiers perform similar jobs, they do so in significantly different ways. Determining the best device is not always easy, nor is integrating devices so that they are able to work together. The selection of appropriate devices and equipment must be based on a personís functional needs and abilities. Integration of the various devices requires an understanding of how each device operates and realistic expectations about system capabilities and desired outcome. This presentation will demonstrate the latest in low vision assistive devices, as well as provide useful information on integrating devices to provide maximum benefit at work, school and home.

One of the first steps anyone should take when working with clients is to make sure that the individual has the devices and software that best fits their visual disability. This is a multi-step process. The first step consists of a low vision evaluation. During this evaluation, the individual is tested to determine what level of vision they have and what devices might assist them to use their remaining vision most efficiently. This is generally performed by an Optometrist who specializes in low vision. You can find listing of low vision optometrists through the American Optometric Association, the American Academy of Optometry or several new web sites (Low Vision Gateway, etc.). Doctors who specialize in low vision generally have access to more devices and technology and are more familiar with the functional implications of the conditions that cause low vision.

A typical low vision evaluation will begin with an extensive history of the patient's visual and general health. It includes questions about the course and nature of their eye condition, their vocational and recreational goals, and their understanding of their condition. Further, it includes questions about devices they may have utilized in the past. Once this is complete, the examination continues with a measurement of the individual's visual acuity at distance and near, a test of their visual fields (measure of their peripheral or side vision), contrast sensitivity and preferred lighting conditions, and eye movements and binocularity. In addition, a refraction should be performed to make sure that the individual has the appropriate spectacle prescription. Based on the results of the above testing, the patient then compares several different devices to determine which works best for them. This device trial sequence is tailored to the individual's needs and opinions. It is also accompanied by a large amount of patient education about the uses and limitations of the particular devices. A common misconception of many patients is that they simply need a new pair of glasses and their vision will be like new. They don't understand or often don't want to accept that they have a functional deficit, which cannot be corrected by conventional glasses, medication, or surgery.

All devices have advantages and disadvantages that a person should explore. When looking at low vision devices, a number of factors need to be taken into consideration: versatility, range of magnification, price, working distance, portability, cosmesis, and visual efficiency while using the device. It is not uncommon for an individual to use several different devices based on the tasks they wish to perform. Some of the newer devices, however, do allow a person to use the device to perform multiple tasks.

The next step is an Assistive Technology Assessment, which fully tests the client on a variety of low vision software and hardware. This assessment exposes the client to the different features of the individual products to show how different features can assist different types of vision loss. It is also possible to use a CCTV with and without a computer to assist in reading paper documents. Along with the software and CCTV, a low vision person might find speech and/or scanners helpful, and these are demonstrated as well.

Once the various optical, software and hardware solutions have been determined, we need to deal with integrating them so that the client can get the best use of all devices and software. This can be best done through training and may involve an on-site visit. Training is a very personalized process, whereby the client learns to use their devices to perform needed tasks. It may involve learning special learning to scan a document with peripheral retina, thus maximizing their visual function.

Some of the most difficult cases are those where a person has a progressive loss of vision and so your initial device is not always your final device, because they either can no longer use the initial device or would prefer to learn the other device in preparation.


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