Eye-Tracker Analysis of the Contrast Sensitivity of Anomalous and Normal Trichromats: A Loglinear Examination with Landolt-C Figures

László Sipos,Ákos Nyitrai,Zoltán Kókai,Krisztián Samu,Attila Gere,Sándor Kovács,Klára Wenzel,Ágnes Urbin

doi:10.3390/app11073200

Abstract

The contrast sensitivity of normal and anomalous trichromats were examined with Landolt-C figures by eye-tracking system. For the measurements, two series of test images (achromatic and colored) were designed. The difficulty levels of the tests were gradually increased after each right answer. In the case of the observation of the ring of the Landolt-C figures, the variables related to fixation duration, fixation count, visit duration and count significantly affected this subject, success or image parameters, and their interactions. The main questions of this study were as follows: Which statistical method is suitable to model the differences between anomalous and normal trichromats? Which eye-movement variables have a significant effect on the investigated parameters and on their interactions? Is there any significant difference between eye-movement variables of normal and anomalous trichromats? How does the survival time of anomalous and normal trichromats change in the case of achromatic and colored figures? The results showed that the right answers of anomalous and normal trichromats can be described with multiple or cross-classified contingency tables evaluated effectively by loglinear regression. The survival analysis showed that normal trichromats are more successful in interpreting colored images, while anomalous trichromats seemed to be more efficient in perceiving achromatic images.

Highlights

Eyes play an important role in our life, in seeing objects of the environment, and in reading books, watching films, or recognizing and discriminating objects and members [1]
The main question of this research was whether anomalous and normal trichromats can be distinguished based on eye movements under different conditions of luminance and chromatic contrast sensitivity
Our main research questions were as follows: 1. Which statistical method is suitable to model the differences between the number of right answers of anomalous and normal trichromats?

Summary

Introduction

Eyes play an important role in our life, in seeing objects of the environment, and in reading books, watching films, or recognizing and discriminating objects and members [1]. The visual acuity of the eye is generally regarded as the most important factor for seeing objects. Objects can generally be better distinguished from each other or from their background if the luminance or color difference is large. Contrast describes the difference in appearance of two or more parts of a field seen simultaneously or successively, a metrics for luminance or color differences. Contrast sensitivity is the capacity of the eye to perceive this difference [2,3]. Vision is created by the contrast sensitivity of the eye and the image processing of the brain [4,5,6]

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