Sustained Fixation Induced Changes in Phoria and Convergence Peak Velocity
2011

Effects of Sustained Fixation on Eye Movement Dynamics

Sample size: 6 publication Evidence: moderate

Author Information

Author(s): Kim Eun H., Vicci Vincent R., Han Sang J., Alvarez Tara L.

Primary Institution: New Jersey Institute of Technology

Hypothesis

This study sought to investigate the influence of phoria adaptation on convergence peak velocity from responses located at different initial vergence positions.

Conclusion

Sustained fixation alters phoria and modifies the peak velocity of convergence steps, with faster responses observed after near phoria adaptation compared to far adaptation.

Supporting Evidence

  • Phoria was significantly adapted after a sustained fixation task at near and far.
  • Convergence far steps were significantly faster than the near steps.
  • Change in phoria and change in convergence peak velocity were significantly correlated for far convergence steps.

Takeaway

When you look at something for a long time, your eyes can get used to it, which can change how quickly they move to focus on other things.

Methodology

The study recorded convergence step responses and near dissociated phoria from six subjects using an infrared limbus tracking system with a haploscope.

Limitations

The study had a small sample size and did not account for potential fatigue effects during the experiment.

Participant Demographics

Subjects were aged 22 to 65 years, with normal binocular vision, including four emmetropes and two myopes.

Statistical Information

P-Value

p<0.002

Statistical Significance

p<0.002

Digital Object Identifier (DOI)

10.1371/journal.pone.0020883

Want to read the original?

Access the complete publication on the publisher's website

View Original Publication