Actually all the claims of illusions on this page look wrong to me.
1. Enlarged curves look bad. The C is too big; it should match the height of the T.
2. Points that overshoot look bad. Even at small size, the points of the N and M clearly stick out past the baseline and cap-height, making them look unbalanced.
3. Things that are smaller look smaller. We make the top half of the B smaller because we like it that way, not because we're trying to make the two halves look the same size. If we want them to look the same size, we should make them the same size.
4. We put the crossbar on the A lower because we like it there. It's not supposed to be centered.
5. Things that are misaligned look misaligned. The middle bar on the E and F are visibly misaligned.
6. Lines appear the same thickness regardless of orientation. The crossbar on the T is obviously thinner than the column holding it up. If you want them to look the same thickness, make them the same thickness.
7. Ovals look like ovals. You don't need to turn a circle into an oval to make it look like a circle. If you want a circle, draw a circle. The O looks obviously wider than it is tall.
8. Diagonal strokes do not look different thicknesses depending on their angle.
9. (This isn't a new point, just an illustration of 6, 7, and 8 together.)
10. Curved lines look the same thickness regardless of orientation. The middle stroke on the S is obviously thicker than the top and bottom. If you want it to look the same thickness, make it the same thickness.
1. Enlarged curves look bad. The C is too big; it should match the height of the T.
2. Points that overshoot look bad. Even at small size, the points of the N and M clearly stick out past the baseline and cap-height, making them look unbalanced.
3. Things that are smaller look smaller. We make the top half of the B smaller because we like it that way, not because we're trying to make the two halves look the same size. If we want them to look the same size, we should make them the same size.
4. We put the crossbar on the A lower because we like it there. It's not supposed to be centered.
5. Things that are misaligned look misaligned. The middle bar on the E and F are visibly misaligned.
6. Lines appear the same thickness regardless of orientation. The crossbar on the T is obviously thinner than the column holding it up. If you want them to look the same thickness, make them the same thickness.
7. Ovals look like ovals. You don't need to turn a circle into an oval to make it look like a circle. If you want a circle, draw a circle. The O looks obviously wider than it is tall.
8. Diagonal strokes do not look different thicknesses depending on their angle.
9. (This isn't a new point, just an illustration of 6, 7, and 8 together.)
10. Curved lines look the same thickness regardless of orientation. The middle stroke on the S is obviously thicker than the top and bottom. If you want it to look the same thickness, make it the same thickness.