Calling all pitchers and pitcher's dads

A curveball actually does break. What is an optical Illusion is the LATE break, actually the break is constant over the whole flight but the eye can't pick it up in the first part of the ball flight.

However a harder thrown curveball with more spin appears to break later since it has less gravity induced fall which means the Notion of late break or falling off the table still has some merits even if it is not actually Happening.

in the end it doesn't matter if it is an optical Illusion because the eye physically is not able to see the break early (although it is possible to pick up the spin and thus do some early projections sometimes).