On the ‘Speckle’ Movements

Since the second half of 1900 century, after the diffusion of the first He-Ne Lasers, several ‘reading key’ on relative movements while seeing a speckle pattern depending on the eye ametropias have been proposed. This paper quotes the development of these different approaches to this phenomenology, as a historical survey, and shows that a complete explanation must involve the vision psychophysics and the retinal structure.