Abstract: A relatively systematic experiment and detailed analysis were madeto find out the law of visual illusion and the structural component offigures of horizontal-vertical illusion and Muller-Lyer illusion. The results of the experiment showed that the major structuralcomponent of the induced horizontal-vertical illusional figures was thevertical and interval horizontal line and not simply the isolated verticalline and horizontal line themselves. The Muller-Lyer illusion wasmainly induced by the angle of horizontal line and oblique lines andthe length of oblique lines. The amount of illusion was larger when bothhorizontal and oblique lines were in the same color, and it was smaller ifdifferent colors were used for the two kinds of lines. An experiment was made to compare various variation of figures.The nature and function of the various structural components of figureswere found, the regular changes in several visual illusions werehighlighted. Based on the facts of this experiment, a relatively detailedanalysis of the eye-movement and visual field theories was made.

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