The blind spot of the eye is the area on the back of the eye (retina) where there are no light receptors as the nerve cord is connected at this particular point. This area cannot detect light or images.
Our brain has adapted to this blind spot and balances the vision usually between both eyes so we never have the feeling that we miss parts of the image.
Ophtalmologic researcher Paul Miller from the University of Queensland in Australia has conducted a study about eye training for this particular "blind spot". The surprising outcome was that the training does not only help to improve vision around the blind spot but it improves vision very rapidly within 3 weeks after the beginning of the training.