1998 Conference Proceedings

Go to previous article. 
Go to next article. 
Return to 1998 Conference Table of Contents


James C. Bliss and Peter Young
JBliss Imaging Systems, 650 Saratoga Ave.,
San Jose, CA 95129 (408)246-5783


In today's world one encounters information from a variety of sources, printed and electronic, and in wide range of type sizes, type fonts, colors, and formats with pictures and graphics imbedded in creative ways. While this variety makes the presentation more interesting and information more readily available for the viewer with normal eyesight, it can present problems for people with visual impairments.

For years magnification has been the main remedy to help people with low vision read. Optical magnifiers were the first generation of low vision assistive products and video magnifiers are the second generation. However, magnification is not the only modification of print that can make it more readable for low vision people. Research (1,2,3) has shown that type font, letter spacing, and color can effect letter recognition in different ways depending on the visual impairment. In addition, with specific visual impairments reading speed can be significantly improved if text is scrolled or moved across the field of view in certain ways.

While magnification alone can make documents readable that are otherwise unreadable with certain visual impairments, this reading is often slow, tedious, and fatiguing. These realizations led us to the development of a document reading system aimed at making reading as fast and easy as possible by people with low vision.

Since visual impairments vary widely, this goal requires the reading system to be adjusted to accommodate the user's vision. For example, optimal adjustment for a person with macular degeneration can be very different than the optimal adjustment for a person with central field tunnel vision.

The following video, which was shown on KRON TV in the San Francisco Bay Area on December 3, 1997, illustrates the reading system, called VIP(TM) (for Versatile Image Processor), which we developed.


The VIP Reading System has the following design features:


Even though VIP systems have been available only for a relatively short time, there are already many VIP Reading Systems being used in individual homes and offices, in libraries, in schools, and in centers for people with visual impairments.

Compared to video magnifiers (CCTVs), VIP Reading Systems are enabling faster and easier reading and much greater functionality at a similar cost. By basing VIP Reading Systems on PC technology rather than television technology, future developments and uses of the hardware are unlimited, compared with the dead-end future of video magnifiers.

Therefore, the future trend will be to replace video magnifiers (CCTVs) based on television technology with PC based reading systems which are becoming the third generation of systems to assist low vision readers.


1. A. Arditi, K. Knoblauch, and I. Grunwald, "Reading with fixed and variable pitch", J. Opt. Soc. Am. A, Vol. 7, No. 10, pp. 2011-2015, Oct. 1990.

2. G. E. Legge, G. S. Rubin, D. G. Pelli, and M. M. Schleske, "Psychophysics of Reading-II: Low Vision", Vision Res., Vol. 25, No. 2, pp.253-266, 1985

3. J. S. Mansfield, G. E. Legge, and M. C. Bane, "Psychophysics of Reading-XV: Font Effects in Normal and Low Vision", Investigative Ophthalmology & Vision Science, July 1996, Vol. 37, No. 8, PP 1492-1500.

Go to previous article. 
Go to next article. 
Return to 1998 Conference Table of Contents 
Return to Table of Proceedings

Reprinted with author(s) permission. Author(s) retain copyright.