The use of contact lenses for the lateralisation of visual input in man.

This research demonstrates the use of a new method of investigating lateralised hemisphere functions. Specially designed contact lenses were used, which directed visual input to either the left or the right cerebral hemisphere. These lenses are an advance on previous methods used in investigating hemisphere function in that they enable the subject to react to stimuli without restrictions on movement and without time limitations on the exposure of stimuli. Investigations of language and visual-spatial functions showed that the lenses appeared to be very effective in lateralising verbal and spatial information.