Even though more exotic tales of CBS imagery receive more attention, geometric patterns seem to be one of the most commonly experienced images. This distinct form of image occurs for somewhere between one in three to two in three people who experience the syndrome.

When we say geometric patterns we are referring to a wide range of styles from the simplistic such as brickwork, fence meshing, netting and grids all the way through to elaborate forms such as wallpaper, the arabesque and kaleidoscopic.

There are usually two ways these geometric patterns are experienced. One is that a certain section of a person’s visual field is covered by the netting or lattice-style imagery. For example, the person looks down at a piece of blank white paper and it becomes covered by some form of regular, repeating pattern. The pattern can be in colour or black and white.

The other common occurrence is that the person experiences a particular pattern that fills their entire visual field (as below). It is experienced as like a curtain or a veil about a foot in front of the person's eyes through which they must look through. This patterned 'curtain' can be very annoying because it is often quite constant and crucially robs the person of some of their remaining vision.