Stripes

I am not sure a zebra would make a very good pet.

Bridget Riley is a leading British exponent of "Op Art." The term was first used in 1964, to describe artists who use colour, shapes and lines to produce surfaces that seem to move and shift. Riley started using just black and white but introduced colour in the mid-1960s, developing a range of optical illusions, which she referred-to as "perceptual abstraction."

Fission (1963) used black circles lined-up on a square white background.  Towards the centre the circles become increasingly distorted giving the viewer a sense of growing distance and perpetual movement. Against her wishes, Riley's images were appropriated by the fashion industry. She felt this misunderstood and misrepresented her work, which was devoted to the "pleasures of sight" which drew on childhood experiences in Cornwall, where she loved the constantly changing sea and sky.

Also in 1963 she produced Fall, which used swirling lines, giving a sense of cloth blown by the wind. 

In 1979 she visited Egypt and developed a palette of colours based on what she saw. Achaean (1981) used parallel vertical lines of those colours.  Although they are rigid, the rhythm of colour creates a sense of movement horizontally across the work.