The Scintillating Starburst illusion appears to have bright rays emanating from its center. If the illusion works, you'll see bright rays shining through the intersection points between the outer peaks of each wreath. Our brain perceives bright dots at these intersection points, because they're the thinnest parts of the wreath, and it then invents rays to connect those dots. (Image credit: Courtesy of Michael Karlovich, Recursia LLC) Do you see the rays?

This next one is called the Hermann grid. Dark spots appear in the illusion that don't really exist. Your brain will probably create dark blobs that aren't really there at the intersections of the white grid lines. Physiologist Ludimar Hermann first documented the illusion in 1870. Researchers are still deciphering the exact mechanisms behind how the grid works, but it could be the response of retinal ganglion cells, which receive and transmit information coming into the eye. Ganglion cells are excited by light, and the intersections of the grid appear dark because there is less stimulation at these points than along the lines. My ganglion cells got excited - did yours?

I can't get this next one to work for me. It is called Confetti Spheres It is an image that tricks the brain into seeing different colored spheres that are, in fact, all the same shade of beige. The colors of the stripes bleed over into our perception of the spheres and messes with our perception of the color behind them. The foreground stripes in each orb correspond with the shade of the orb behind. We see the orbs in their true color of beige when the stripes are removed or pushed to the background. Could you get your eyes to do that?

Lastly (for today) we have the curvature blindness illusion. Humans can perceive a wavy line as an angular zigzag. In the image above, all of the lines are the same wavy shape, but half of them appear to be zigzagging in the gray section. Kohske Takahashi, a psychology professor at Chukyo University in Japan, documented this illusion in a 2017 study published in the journal i-Perception. Takahashi suggested that the brain has a separate mechanism for identifying curved and angular shapes, and that the perception of angles may take priority when they compete in the curvature blindness illusion. Given a choice, I prefer looking at curves. Did your brain see both types?