After-effects are perceptual phenomena that occur after prolonged exposure to a particular stimulus. These effects can lead to distortions or illusions in our perception of subsequent stimuli. The tilt illusion, the luminance contrast effect, and the color illusion are all examples of after-effects.

1. The Tilt Illusion:
The tilt illusion is a perceptual phenomenon where tilted lines appear to be more vertical or horizontal after prolonged exposure to lines of a different orientation. For example, if you stare at a set of tilted lines for a while and then shift your gaze to a set of vertical lines, the vertical lines may appear tilted in the opposite direction. This after-effect occurs due to the adaptation of the neurons in the visual system that respond to line orientation. The neurons become fatigued or desensitized to the adapted stimulus, leading to a shift in perception.

2. The Luminance Contrast Effect:
The luminance contrast effect is an after-effect that occurs when the perception of brightness or darkness is altered after exposure to a high-contrast stimulus. For instance, if you stare at a bright light source for some time and then look at a dimly lit area, the dimly lit area may appear even darker than it actually is. This after-effect is caused by the adaptation of the neurons responsible for processing luminance information. The adaptation leads to a shift in the perception of brightness and darkness.

3. The Color Illusion:
The color illusion is an after-effect that occurs when the perception of color is altered after exposure to a particular color stimulus. One well-known example is the complementary color after-image. If you stare at a red object for a while and then shift your gaze to a white surface, you may perceive a greenish after-image. This after-effect is due to the adaptation of the color-sensitive cones in the retina. The cones get fatigued or desensitized to the adapted color, resulting in the perception of its complementary color.

In conclusion, the tilt illusion, the luminance contrast effect, and the color illusion are all examples of after-effects. They demonstrate how our perception can be influenced and distorted by prolonged exposure to specific stimuli.