Tunnel vision is a vision defect where objects cannot be seen unless they are near the center of the visual field.
There are two types of cells in the retina that respond to light: rods and cones. The cones are concentrated in the center of the retina––known as the macula––and are responsible for detailed color vision. The rest of the retina is covered with rods, which are responsible for peripheral and night vision. Tunnel vision typically results from eye conditions that inhibit the function of the rods, causing loss of peripheral vision, while the cones continue to function.
Tunnel vision can be also accompanied by night vision problems.
Tunnel vision can be a symptom of: