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Fixation disparity

Improved compatibility and success rates of varifocal lenses.



To achieve better compatibility and higher success rates with varifocal lenses, it is essential to understand the laws of binocular vision and to determine the individual requirements of each individual wearing varifocal lenses. The project is divided into several phases:

Basic research into fixation disparity

As part of a large study specifically designed to research fixation disparity, the binocular characteristics of a group of test subjects are recorded and the effect of "prismatic varifocal lenses" are being explored. It could be shown that the use of prismatic lenses had an impact on varifocal lens tolerance. This study suggests that there is a benefit from prismatic correction in varifocal lens wearers.

Development of a device for determination of relevant fixation disparity parameters

  • Determining the measurement methodology
  • Defining the measurement apparatus and electronics
  • Defining the programme logic as well as the implementation and testing of the measurement procedure

Project information

Project partners Hoya Lens (Germany) GmbH; Leibnitz Institut für Arbeitsforschung an der TU Dortmund (Leibnitz Research Centre for Working Environment and Human Factors)
Execution FHNW Institute of Optometry
Project team Professor Dr. Roland Joos