In this thesis we analyze how the visual perception of a rectangular test, achromatic (gray: β = 0.5) or color (red, green or blue), to contemplate it through a rectangular grating (Ronchi grating) with a constant modulation ratio (rm = 0.5) achromatic (white-black) or monochromatic (white-red, white-green or white-blue).
In all cases has been foveal vision, binocular and oriented perpendicular to the segments of the grating. The conclusions have been made with four observers (two men and two women) with emmetropic or corrected vision and have been evaluated thirty-six tests.
The results indicate that as is known from the Gesthaltian theory, the vision of a test depends on the scenery in which it is immersed and on the optical conditions with which we observe the background grating.
The observation variables were:
	1. Orientation of the grating and rectangular test.
	2. Ratio between the Bezold effect produced by the grating in the rectangular test and the colors of the test or of the grating.
	3. Ratio of the value of the Bezold effect (chromatic expansion) occurred in the rectangular test by the Ronchi grating with the frequency of the grating.
The Bezold effect peaks (in this thesis) in the horizontal orientation of the grating with perpendicular sequence.
The blue and green colors are more influenced by the Bezold effect, having obtained similar results. Red has less influence, always under the blue and green results.
In all cases there is a linear ratio between the Bezold effect and the grating frequency.