This image was modified from the figure of 'The Perception of Stabilized Retinal Images' from the Neuroscience Fifth Edition Textbook (Purves et al.). In the figure, fixational eye movement is displayed by the purple lines. The direction of the movement is shown by the arrows. Microsaccades are indicated by the straight lines. Ocular drift is indicated by the zig zag lines. These lines demonstrate how the two types of eye movement change the retinal stimulus the entire time the eye is fixated.