11. This size difference in area V1 correlated with the 17 % illusory difference between the perceived visual angles . 12. The determined threshold was a height of 45 degrees of visual angle for the height of the surface. 13. Size and shape were determined by the visual angle subtended at the eye combined with perceived distance and orientation. 14. They are outside because moving away from the computer screen has decreased the visual angle of the lilac spots. 15. The image is magnified, perhaps giving it a visual angle similar to the real scene the picture is depicting. 16. In fisheye lenses, the visual angle is close to or more than 180 degrees in at least one direction. 17. It is replaced by a perceptual SDIH, in which the visual angle is replaced by the perceived visual angle. 18. It is replaced by a perceptual SDIH, in which the visual angle is replaced by the perceived visual angle . 19. The difference between those real directions ( ) is, again, the visual angle " ? ". 20. The diagram shows the relative acuity of the human eye on the horizontal meridian in degrees visual angle from foveal vision.
