PERCEPTION• The images are actually identical, but the tower on the right seems to lean more because the human visual system treats the two images as one scene.• Our brains are conditioned to expect parallel towers to converge toward a common vanishing point, but because the tower on the right does not converge, our visual system interprets that it is leaning at a different angle• . A common example of this conditioning is the way 3D movies and 3D TVs trick our minds into believing that images are actually coming out of the screen, when in fact they are not. Our minds are conditioned to believe 3D images move in 3 dimensions.• With a bit of technical help, we can trick our minds into visualizing this on a 2D screen. Below is a perspective drawing with three vanishing points of what our eyes expect
• Hold your head steady and fix your eyes on the dot in the center of the picture. The colored dots will seem to disappear in a few seconds. The effect is due to retinal fatigue which occurs when the afterimage of an object cancels the stimulus of the object on the retina. The effect is most pronounced when the objects do not have well-defined edges that are detectable by small eye movements
• The circles appear to rotate when you move your head closer and further away from the screen while looking at the dot in the center. Our peripheral vision interprets the relative increase or decrease of the image in the retina as rotational motion of the slanted lines.
• Blind Spot Experiment The retina is the part of the eye covered with receptors that respond to light. A small portion of the retina where the optic nerve connects to the brain has no receptors. An image that falls on this region will not be seen. Close your right eye.
Close your right eye. With your left eye, look at the L below. Slowly move your head closer or further away from the screen while looking at the L. The R will disappear when your head is approximately 50 cm (20 in) from the screen. You can repeat the experiment with your right eye by looking at the R.
PERCEPTIONIllusory Contours Although there are only circles with sections taken out of them, our eyes strive to see triangles. The sides of the triangles may appear curved when the angles of the sections do not add up to 180 degrees
PERCEPTIONRotating Wheels The circles appear to rotate when you move your head closer and further away from the screen while looking at the dot in the center. Our peripheral vision interprets the relative increase or decrease of the image in the retina as rotational motion of the slanted lines.
PERCEPTION• Warped Squares? There are no curved lines in these figures. You can use a ruler to check it out. The diagonal patterns created by the tiny squares distort the perception of the pictures