The Eye-Camera and its Application

At the time when Werner Louw embarked on the Audiblox program the eye-camera was still a very popular instrument to assess reading efficiency. The eye-camera measures the time it takes a person to read a piece of text, and from this his reading speed per minute is calculated. The movements of the person's eyes are photographed and represented on a reading graph.

This reading graph can be analyzed to determine the number of eye fixations that occurred during reading. When a person reads, his eyes engage in a series of quick movements across the page with intermittent fixation pauses. The more often the eyes have to pause for fixations, the slower the reading speed will be. A dyslexic person will be inclined to pause more often, and the duration of each fixation will be longer than that of the typical reader. After this, it is possible to calculate the person's recognition span. This refers to the average number of words the person can recognize in one fixation, as well as to the average duration of such a fixation.

By analyzing the reading graph one can also determine whether any regressions occurred in the eye movements of the reader. A regression occurs when the eyes moves toward the left to look again at words that had been covered already. The dyslexic person is inclined to have more regressions than the normal reader.

After reading the piece of text, the person doing the test is required to answer a number of questions on the contents. This is to determine his comprehension, which is expressed in a percentage. Lastly, the relative reading efficiency can be calculated, which is expressed in year levels.

The test results of Werner are presented below. The solid line represents the first reading test on 9 March 1990, the thin dashed line the retest on 5 August 1990, and the thick dashed line the second retest on 12 February 1991.