 Chubb effect estimates that when an object is viewed through an imperfectly transmitting medium, it increases or decreases the apparent brightness or dullness of the target patch, even when luminance ratios and spatial frequencies remain the same.Lotto and Purves (2001) doubted that illusory perceptions of brightness were explained as consequences of lateral inhibition.If that were the case, the perceived difference in brightness of target elements, illustrated in Figure 3 (A), would be largely unaffected by the surrounding field in Figure 3 (C), which exhibits lower spatial contrast than the target, which matches the observations.