Vision span

[3] The brain creates the illusion of having a greater visual span by automatically and unconsciously moving the center of vision into any area of interest in the field of view.

It has been suggested that the fixation span can be stretched through training (meta guiding) to take in as much as a line for the purpose of skimming or speed reading.

[7] However other sources suggest that using this method can result in a severely reduced comprehension rate in comparison to normal reading ("rauding").

[8] It is claimed that such speeds also require great practice, and extremely rapid eye movements, although research suggests that such training is not possible.

Similarly to the reading span, the Facespan might be modulated by difficulty,[9] expertise,[10] age,[11] disorder [12] and other idiosyncratic differences between individuals.

Previous study revealed that the Vision span is more accurately defined in number of characters rather than in visual angle.