Periphery is that allow all sides without turn your heads or moving your eyes. It help us in motion and walk without crashing into things. It is that you use is at the corner of eyes that help you in seeing things without turning heads. At the peripheral, there are found at the periphery of the eyes. If some one has problem , then it means the person has not a wide area to see. If central area is fine even then the person is not able to see things widely.
Moderate and severe cases of peripheral vision loss create the sensation through narrow tube. A condition is referred as to the Tunnel vision.