Normal people do not perceive an “empty” region in the portion of their visual field corresponding to the physiological blind spot. Instead, the visual system perceptually fills in the blind spot with information surrounding it. Similar types of perceptual filling in also occur in patients with pathological monocular and binocular homonymous scotomas.1 2 Furthermore, stabilising the image of a spot on the retina leads to perceptual filling in of the spot with the surrounding background.3 Perceptual filling in of stabilised images can also be demonstrated for colour, brightness, and texture.4-10 Safranet al have …