Teller Acuity Cards and Teller Acuity Cards II™

Copyright ©1997 Anthony Young

The Teller Acuity Cards and Teller Acuity Cards II™ offer eye care practitioners and vision researchers a rapid and reliable method of assessing visual acuity in infants, children, and nonverbal adults. The set of seventeen cards allows clinicians and researchers to measure an infant or child's ability to resolve black and white striped patterns printed on the cards.

The Teller Acuity Cards were created over twenty years ago and have been distributed as a product since 1986. The original developers have continued to monitor the quality of the product as it is supplied to users. Using a registered trademark as the dominant type of intellectual property, the Teller Acuity Cards retain a uniquely identifiable presence in the marketplace, and the developers retain quality control assurance over the development and production of their design. Over the last two decades, the Teller Acuity Cards have proved to serve a very real need in current ophthalmic, optometric, and pediatric practice and research concerning the development of vision in infants and young children.

The original licensee for the Teller Acuity Cards ceased distribution of the Teller Acuity Cards in 2003. Since that time, Digital Ventures has assisted the developers to refine the plans for Teller Acuity Cards II and bring them to the marketplace. Digital Ventures is pleased to help manage the trademark, and the enabling license for the commercial version of the Teller Acuity Cards II.

Description

Standard assessments of adult visual acuity are based on subjective verbal responses from the patient. You can remember being asked to read a set of letters from a chart by your eye doctor. With well-motivated adults this type of procedure is adequate. Assessment of vision in infants and pre-verbal children, however, will necessarily require unique strategies.

The Teller Acuity Cards developers found that by judging infant’s visual attention to each of a series of cards containing stripes of different widths (spatial frequencies), they could change time-consuming laboratory testing techniques into a rapid acuity test suitable for use in clinical settings. The Teller Acuity Cards product is based on specifications formed from their research. The standard procedures give practitioners or researchers a method by which to quantify a child’s reaction to the cards.

Development Background

The Teller Acuity Cards were developed at the Department of Psychology, University of Washington, Seattle, Washington through the efforts of Drs. Davida Teller and Velma Dobson and their research team. Their early research centered on the use of preferential looking (PL) and forced-choice preferential looking (FPL) techniques with infant macaque monkeys and later, human infants in a laboratory setting. In the FPL procedure, an infant is presented a set of black-and-white stripes placed on the right or left side of a card, against a contrasting gray background. An adult observer uses observations of the infant's eye or head movements to judge which side of the display the grating is on. Although this formal test was statistically reliable and well suited for laboratory work, an accurate test required up to 80 trials per infant, and could take as long as an hour to complete. In addition, the qualitative aspects of the child’s behavior had to be discarded in formal testing.

The time-consuming nature of repeated testing, inability to successfully test certain age groups, and bulkiness of equipment convinced the developers of the need to create a more efficient technique for clinical use. The Teller Acuity Cards were developed to measure the infant's acuity with a set of smaller, portable cards. Once the cards were developed, the team began rigorous testing of validity and reliability, and found that testing with the cards gave results comparable to FPL laboratory techniques, but within five to ten minutes of testing.

As the researcher’s specifications were turned into a commercial product, quality control standards were created to maintain the validity of the new cards. Further testing by Dr. Luisa Mayer at Harvard University allowed for the creation of norms against which to compare the vision of an infant at risk for nonnormal visual development. The Teller Acuity Cards have also been used by the original developers and others to assess the vision of older, non-verbal children and adults.

The original research group has dispersed to different institutions; Dr. Velma Dobson is now at the University of Arizona, and Dr. Luisa Mayer remains at Harvard University. Dr. Teller is still with the University of Washington. However, all are still engaged in reviewing the Teller Acuity Cards trademarked standard and in using the cards in their research. To read further about the cards development and their use in clinical and laboratory testing, please view the citations in the Publications section.

Technology Benefits

Just as the Snellen (letter) chart is the standard used in measuring adult visual acuity, the Teller Acuity Cards are the standard diagnostic tool for evaluating visual acuity in infants and non-verbal children and adults. The cards allow estimation of acuity in two to six minutes per eye as opposed to more time-consuming laboratory methods, while showing similar high levels of accuracy and reliability. Because of their portability and ease of use, they work equally well in laboratory and clinical settings.

Future Goals

• The Teller Acuity Cards can be used in the research setting as well as the clinic. By providing a diagnostic tool measuring visual acuity in infants and nonverbal populations, the Teller Acuity Cards will enable further research in the causes and treatments for non-normal visual development.
• The Teller Acuity Cards II are now being manufactured and distributed by the Stereo Optical Company. This company developed new lamination techniques for the cards, thus changing the contrast of the gratings and prompting the need for development of new norms.

Digital Ventures’ Role

Digital Ventures’ staff assisted the Teller Acuity Cards II developers in the following areas:

• Managing a trademark is difficult when the University and a manufacturer want to be active in research and/or production at the same time. However, developing and maintaining quality standards is critical to consumers, who want to know that the Teller Acuity Cards II meet the same standards as the original Teller Acuity Cards, which have been tested and validated in the field. Thus, Digital Ventures helped Stereo Optical, the licensee, and the Teller Acuity Cards II developers to agree to manufacturing quality standards, and to develop a procedure for continually checking, validating and maintaining those standards.
• Digital Ventures filed and will maintain the trademark “Teller Acuity Cards” and “Teller Acuity Cards II” with the U.S. Patent & Trademark Office.
• Consistent with all projects, Digital Ventures drafted the license agreement, managed internal rights, and manages revenue created by the distribution of the Teller Acuity Cards II by Stereo Optical.

Contact

Dr. Davida Teller
University of Washington
Department of Psychology
Guthrie Hall
Box 351525
Seattle, WA 98195
E-mail: dteller@u.washington.edu

Publications

The following citations review the early development and clinical trials of the Teller Acuity Cards:

• McDonald M.A., Sebris S.L., Mohn G., Teller D.Y., and Dobson V. 1986a. Monocular acuity in normal infants: The acuity card procedure. Am J Optom Physiol Opt 63: 181-186.
• Preston K.L., McDonald M.A., Sebris S.L., Dobson V., and Teller D.Y. 1987. Validation of the acuity card procedure for assessment of infants with ocular disorders. Ophthalmol 94: 644-653.
• Sebris S.L., Dobson V., McDonald M.A., and Teller D.Y. 1987. Acuity cards for visual acuity assessment of infants and children in clinical settings. Clin Vision Sci 2: 45-58.
• Teller D.Y., McDonald M.A., Preston K., Sebris S.L., and Dobson V. 1986. Assessment of visual acuity in infants and children: The acuity card procedure. Devel Med Child Neurol 28: 779-789.

The following two references provide more recent updates.

• Dobson, V. 1994. Visual acuity testing by preferential looking techniques. In Isenberg, S.J. (Ed). The Eye in Infancy. St. Louis, MO: Mosby-Year Book, Inc. pp 131-56.
• Teller, D.Y. 1997. First Glances: The Vision of Infants. Investigative Ophthalmol & Visual Sci 38: 2184-2203.