Headaches, dizziness, and nausea are all common side effects to viewing a Bridget Riley painting. The cause of this effect may lie in her childhood. Riley, who was born in London in 1931, grew up with her mother in Cornwall, England. John Elderfield explains that "her mother would take Bridget and her sister on walks in a varied landscape and point to the visual sensations of things-the colors, the illumination, the elusive transitions-encouraging them to notice surprising effects" (30). Such are the sensations of Riley's paintings: the eye is continuously deciphering the piece, following its twists and turns, trying to understand what it sees. Riley's extraordinary use of color produces a radiant energy in her work; she has continuously stated that her paintings are very much alive. However, Bridget Riley achieved notoriety with her use of black and white. Color both intimidated and intrigued her, and she didn't use it for the first fifteen years of her work. Her first applications of color in her work were mixed with gray, her first full-color works only consisted of pure red, blue, and green. Today, the artist uses a wide spectrum of color in her work. This paper will explore the influences to Bridget Riley's work, the stylistic periods of her painting, and her technique allows the image to create "visual anxiety."

The major influences to Bridget Riley's work all contributed to her eventual decision to work in color and the way in which she would apply color. In 1958 Riley caught an exhibition featuring the work of Jackson Pollock. Pollock's freely rhythmic, vibrant, linear compositions impressed Riley. Piet Mondrian was another influence to Riley's work. Riley especially admired Mondrian's "Boogie Woogie" paintings, noting that Mondrian was "putting totally at risk the stability and equilibrium which had been central of his achievement" (Craig-Martin 53). Riley was particularly impressed with Mondrian's Composition with Grid: "the grid remains constant while the lines thicken and thin and planes emerge and recede" (Spalding 17). This helped her establish her own line patterns in both her black and white and early color work. Futurist painters like Giacomo Balla attempted to uncover the inner life and emotion of lines and color; the futurists' desire for the view to participate in the work would also influence Riley.

Bridget Riley's work can be divided into several stages, each stage a progression toward her vibrant and free use of color. Her black and white period, which roughly occurred between 1961 and 1966, is where she achieved national recognition. It is also in the black and white period where Riley was classified in the op-art movement of the 1960s (Riley to this day does not like the classification, she repeatedly states that she has never studied optics). The paintings from the black and white period are composed of geometric shapes, varying in widths, creating an optical effect on the viewer. "Blaze 1" (1962) is an example of her work from this period. Composed of a depth of zigzags in a circular shape, the painting radiates intense optical energy. Many critics during this period cite that her paintings attack the viewer. Many of Riley's designs from this period, because of their visual intensity and popularity, were plagiarized and reproduced commercially on billboards, magazines, and even dress skirts. Perhaps as a response to the disgust of her black and white reproductions in popular culture, Riley began to gradually drift away from pure black and white, using variations of gray tones instead. This would begin her interest in color.

A next stage of Riley's work is a transitional period, going from Riley's use of black and white to her use of color. This period is commonly called the period of "Colored Gray" paintings; this period lasted roughly from 1966-1967. "Cataract 3" (1967) is a transitional work-an opposition between color and tone-and is described by John Elderfield as "an overwhelming liquid flow" (32). Red and a subtle turquoise appear in the center of the piece, surrounded by stripes of gray paired with turquoise. A series of diagonals in the piece emit a bright vibrance of color. According to Robert Kudielka, "Color seems to have enabled [Riley] to proceed from the disruptive shock of making us 'see' to the full experience of what looking her way feels like" (18). However, Riley's transition into color was difficult. Riley, in an interview with Michael Craig-Martin, explains the problems with introducing color to her work: "In my black and white work I was dealing with staple, easily recognizable forms. If you think of a square, a circle, a triangle, no matter what size it may be, you know exactly what form you can expect to see. But if you say red, yellow, or blue you do not know at all what shade of color you will be looking at. There is no certainty, no precise concept upon which you can rely..." (56). Riley realized that the basis of color is instability-one never can fully imagine the result of color interaction in planning stages, the interaction may look one way in a sketch, but in a large scale painting, the interaction may be different.

Riley's paintings morphed again into a series termed the "Lozenge" or "Zig" period of the late 1980s to mid 1990s. Riley's paintings during this period are characterized by "dense, inextricably layered structures built up piece by piece with colored papers of different sizes" (Kudielka 44). These colored papers are rhomboid like shapes (called "zigs" because the zag direction is missing). "Galliard" (1989) almost resembles a scrambled cable channel: "white loosely indicates a horizontal counter-balance, red and orange dominate the full stretch of the opposite diagonal, black and yellow circulate in open, unconnected loops, and a range of blues, supported by greens and violets, permeates the constantly shifting space" (Kudielka 36). "Parade 1" (2000) is another example from this period, but uses curved pieces of paper instead of rhomboid forms.

Riley creates her paintings by designing careful, intricate drawings and carefully observes as her assistants who actually paint the final piece. Riley gives her assistants precise orders and exact measurements. The project is more conceptual for her, more brains than brawn. By delegating tasks to her assistants, Riley can observe from afar her creation and make refinements and decisions as necessary. She can watch the whole piece as it is done by hand. Riley does not generally employ screen printing or any other mechanical means to produce her work.

Bridget Riley's paintings dazzle the eye. But her goal is not to motivate discussion about the technique of optical illusion, but of what you get out of the experience. "I want my paintings to exist on their own terms. That is to say they must stealthily engage and disarm you. There the paintings hang, deceptively simple - telling no tales as it were - resisting, in a well-behaved way, all attempts to be questioned, probed or stared at and then, for those with open eyes, serenely disclosing some intimations of the splendors to which pure sight alone has the key" - Bridget Riley

While her work may create headaches, it is more painful to turn away.