Quantitative study of the Muller-Lyer illusion in schoolchildren
without and with ophthalmopathology
S. I. Rychkova
Institute of Information Transmission problems, RAS
Quantitative study of the Muller-Lyer illusion in comparison with regular estimation by sight has
been performed in schoolchildren of different age. In our study, 157 healthy pupils and 162
pupils with ophthalmopathology were tested. The mesurements were performed using: 1) the
interactive software that allowed to control the length of a test line to make it equal to the
reference line in the test fi gures for the observation of illusion or the length estimation by sight;
2) printed test charts with different variants of test images. The second way allowed us to study
the range in which unequal test and reference lines can be perceved by a child as the equal ones.
It has been established that the power of the Muller-Lyer illusion decreases with age both in
healthy pupils and in pupils with ophthalmopathology. However, this age dynamics is less
pronounced in pupils with ophthalmopathology than in healthy pupils, suggesting a slowing of
the development of visual functions in children with ophthalmopathology.
Key words:
MULLER-LYER ILLUSION, REGULAR ESTIMATION BY SIGHT, AGE DYNAMICS,
OPHTHALMOPATHOLOGY