It appears that you can expand your visual field (Image: Tui De Roy/Science Photo Library/Getty)

We hardly notice our blind spots, but it seems we can shrink them if we want. It just takes a bit of practice.

Take a look at the dot and cross below. Closing your right eye, focus on the cross, and move your head slowly forwards and backwards – at some point, the dot will vanish. That’s because your optic nerve joins your retina at that point, leaving a spot with no photoreceptors. You don’t normally notice it because your brain fills in the empty spot with information based on what you see around the spot.


But people often report a gap in their field of view that is bigger than can be accounted for by the retinal blind spot, says Paul Miller at the University of Queensland in Brisbane, Australia. This set his team wondering whether the gap could be reduced.

They devised software that displays a circle slightly bigger than the hole in someone’s visual field. The circle has stripes within, and volunteers were asked which direction these moved in.

The circle’s size was adjusted to be just large enough for participants to get the direction right about 70 per cent of the time – much better than by chance. Over time, volunteers were able to retain this level of accuracy even after the circle had shrunk by about 10 per cent. “People developed sensitivity to things they apparently could not see at the beginning of the training,” says Miller.

Improving impairments

Only 10 volunteers took part, and Miller says that the training would not improve the tennis of someone with good sight, for example. “But it could have profound benefits for people with cases of pathological localised blindness, such as age-related macular degeneration,” he says. “If we can train people to be more sensitive to movement in and about regions of localised blindness, we might improve performance when doing important tasks like driving a car,” he says.

If the effect is replicated in larger studies, it shows “there is a level of plasticity throughout life at the cortical level,” says James Bourne from Monash University in Melbourne, Australia. He says similar effects have been shown in humans when there has been brain damage after stroke, but not after eye damage. If this plasticity is still present in people with macular degeneration, then it might be a useful treatment.

Journal reference: Current Biology, DOI: 10.1016/j.cub.2015.07.026