Coope approaches the problem of trying to find the best visual fit of circle to a set of 2D data points.

The threshold is then adjusted so that this visual fit is optimum in the aggregate as judged by the user.

In other cases, more bizarre perceptions follow, including geometrically regular, cursive floating impairments in the visual field, and "visual fits" in which (for example) objects on the floor to the patient's lower right are momentarily perceived as floating in the air to his upper left and rotated 180 degrees through space.