Have you ever had someone you know show you a cool website that has an optical illusion, and you just can’t understand why your eyes trick you in this way? Well, prepare to be enlightened.

Color Illusions:

Optical illusions are numerous and one of the most interesting are color illusions, These types of optical illusions are such that your eyes see different colors when, in reality, the two colors in question are actually identical. What causes this? The main cause of these color illusions is color constancy. Color constancy helps our brains make sense of objects, even when there is a low reflection of light off the object. Cone cells are cells in our eyes that are critical in the process of seeing color. As these cones register different wavelengths of light, neurons in the visual cortex work to translate the cone activity into “color”.

Take a look at this optical illusion for example:

In this illusion, square B appears to be a white square, while square A appears dark. This is where color constancy strikes. Since square B is obscured by a shadow, and alternate squares are white, our brains assume that square B must be white. In addition, since square A falls on a grey pattern, our brains assume that square A cannot be the same color as square B, and thus, we see a distinct difference. However, if you look carefully, you will see that they are indeed the same color. Color constancy is so impactful here, that, If I were to tell you that the square to the right of A is the same color as square B, that would be more believable. You might even see the resemblance for a while. However, after looking closely, you can see that square B is darker. This shows that the context of other objects can trick our brain.

Optical illusions are very interesting to see. They trick your brain in numerous ways, such as hallucination of colors. How dark or light a color appears depends on the context and what color is next to it. Color constancy plays a pivotal role in many of these illusions.

Sources:
1. How Optical Illusions Work