https://www.piotrlukaszkiewicz.pl/05_vertical-horizontal/?lang=en https://www.piotrlukaszkiewicz.pl/05_vertical-horizontal/?la... From reading this, the error

https://www.piotrlukaszkiewicz.pl/05_vertical-horizontal/?lang=en https://www.piotrlukaszkiewicz.pl/05_vertical-horizontal/?la... From reading this, the error with circles appears to be <1%. Also, obligatory mention whenever horizontal-vertical illusion comes up: https://www.nippon.com/en/japan-topics/c12403/ https://www.nippon.com/en/japan-topics/c12403/