Best. Illusion. Evah!

Best. Illusion. Evah!  This is a really powerful optical illusion.  All the lines in the image at right are sinusoidal curves.  Yes, even those lines that appear to be triangular.  Click the image to embiggen it, then put a ruler up against the “straight” lines.  They're curved exactly like the ones that appear curved!

Most illusions I can sort of “talk” myself into a state where the illusion disappears.  Not this one.  Much more on it here...