Sometimes op art will toy with the confusing way that the eye and brain strive to make sense of what isn’t there. Although we realize the visual trick, we can’t ignore it. In this typical pattern, positive and negative forms give the clear impression of circles, an effect that Yaacov Agam (born 1928) capitalized on for some of his op-art works.

The socks shown here, named after Yaacov Agram, are knitted in the stranded technique with two balls of the same color-striping yarn. For the effect to work, the individual stripes should continue over ten or more rounds. Work with two balls of yarn, beginning each at the start of a different color and be sure work both balls from either the outside or inside. Doing so prevents the same color from appearing from both balls at the same time. The shifted color stripes of two balls of the same yarn add to the confusing effect of the positive/negative circles.

Sizes: About 8” (20.5 cm) foot circumference, unstretched, and 10 (10½, 11)“ (25.5 26.5, 28 cm) foot length from back of heel to tip of toe (minor length adjustments possible). To fit U.S. women’s shoe sizes 8–9 (10–11, 11½–12½); European shoe sizes 39–41 (42–44)