Stereovision in children is typically tested by random-dot stereogram, which reveals no information if viewed with only one eye. However, tests for children who cannot yet speak require special glasses, and some tests for these children provide only subjective results. Researchers from the University of Münster in Germany are testing a technique that may be more useful for preverbal children because it tests stereovision in a more natural way.

It involves recording eye movements with an infrared photo-oculography system while a random-dot stimulus is shown on an autostereoscopic computer monitor. This type of monitor allows viewing of full-color 3-D images without special glasses, and the eye movement recordings provide objective results.

To test the technique, a random-dot stimulus was shown on the 3-D display to 56 children, 38 of whom had vision problems and 18 of whom had normal vision. All were around age 5.

As detailed in the November issue of Investigative Ophthalmology & Visual Science, the results showed the test to have an overall accuracy of 95 percent.

Although the children tested were not preverbal, the researchers believe the technique holds potential for those who are. Further studies are needed to test its use in younger children as well as its ability to screen for vision problems.