You may not notice it, but, like everybody else, your eyes actually have a tiny blind spot that is incapable of receiving light and therefore cannot send visual messages to the brain.

Small as it already is, the blind spot can actually "shrink" and further aid in the treatment of visual impairments, like those caused by macular degeneration.

Researchers from the University of Queensland in Australia conducted a small study to test the effects of a specific type of eye training to the shrinking of the blind spot. Results of the training which they referred to as "direction-discrimination task," were published online in the journal Current Biology.

In the experiment, the researchers gathered 10 people and conducted eye training for 20 days. For the task, the participants wore an eye patch and were shown an image of a ring through a computer monitor. The ring was directed toward the blind spot of each person's eyes. Moving through the ring were waves of light and dark bands. The participants were then asked to identify to which direction the waves went. For a second task, each participant was also asked what the color of the ring was.

Throughout the experiment, the ring was also randomly manipulated. At times, it would circle the blind spot,but was also sometimes situated right within the blind spot.

The researchers explained that they designed the exercises in a way that would allow the participants to judge the direction of the waves correctly at about 70 percent of the time. The training exercises were done in repeated simulation, and by the end of the 20-day experiment, the researchers found that the blind  spot of each of the participants have "shrunk" by approximately 10 percent.

"At the end of the training, there were improvements in the ability to correctly judge both the direction and the color of the waveform," said UQ's Paul Miller, a psychologist who is also the author of the study.

The researchers however explained that the improvement wasn't an actual shrinking of the blind spot. Rather, the study revealed that the repeated simulated training made the receptors around the blind spot more sensitive to light and visual stimulus. The rest of the eye becomes more sensitive to the weak signals directed toward the blind spot, improving the participants' vision around that field.

"We did not confidently expect to see much reduction in functional blindness, as you can never develop photosensitivity within the blind spot itself," added Miller, who emphasized that with the 10 percent reduction of the blind spot in their study, similar treatments may also be found to be effective in other forms of blindness, or further aid in the development of technologies like retinal stem cell therapy or bionic eyes. 

Photo: Les Black | Flickr