Multifocal techniques are used in electroretinogram and visual evoked potential recordings to separate the responses originating from the stimulation of different locations in the visual field (and thus different retinal locations).
All visual field locations are stimulated in parallel with their individual stimulus sequence.
Due to the independence of the stimulus sequences, the responses for each visual field location can be extracted using mathematical algorithms.
Mutifocal techniques, in particular the multifocal ERG, are used in the diagnosis of ophthalmological diseases.
The multifocal technique was developed in the early 1990s in the laboratory of Erich Sutter at the Smith-Kettlewell Eye Research Institute[1][2][3]