May 1992
Volume 33, Issue 6
Free
Articles  |   May 1992
Differences in tests of aniseikonia.
Author Affiliations
  • G McCormack
    New England College of Optometry, Boston, MA 02115.
  • E Peli
    New England College of Optometry, Boston, MA 02115.
  • P Stone
    New England College of Optometry, Boston, MA 02115.
Investigative Ophthalmology & Visual Science May 1992, Vol.33, 2063-2067. doi:
  • Views
  • PDF
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      G McCormack, E Peli, P Stone; Differences in tests of aniseikonia.. Invest. Ophthalmol. Vis. Sci. 1992;33(6):2063-2067.

      Download citation file:


      © ARVO (1962-2015); The Authors (2016-present)

      ×
  • Supplements
Abstract

The New Aniseikonia Test (NAT), a hand-held direct-comparison test using red/green anaglyphs, has several potential advantages as a screener. We compared the validity of the NAT to that of the Space Eikonometer in three experiments: (1) aniseikonia was induced by calibrated size lenses in a double-blind study of 15 normal subjects; (2) habitual aniseikonia was measured with both instruments in four patients; and (3) eight of the normal subjects were retested with a computer-video simulation of the NAT. The NAT underestimated induced aniseikonia by a factor of 3 in the normal subjects and underestimated habitual aniseikonia in four patients. The Space Eikonometer correctly measured the magnitude of induced aniseikonia in the normal subjects. The simulation test did not show underestimation in the eight normal subjects. We could not attribute the NAT's underestimation of aniseikonia to the red/green anaglyph method, printing error, psychophysical method, or the direct-comparison test format. We speculate that the NAT induces a different sensory fusion response to aniseikonia than do the other tests, and that this altered sensory fusion response diminishes measured aniseikonia. We conclude that the NAT is not a valid measure of aniseikonia.

×
×

This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.

×