Tunnel vision is a medical condition that results in a loss of peripheral vision. As a result, the patient can only see objects from within a circular field.

There are many possible causes of tunnel vision. Blood loss to the brain, for example, can lead to tunnel vision, as can a tumor pressing against the optic never fibers. A person who is exposed to air that has been contaminated by oils and hydraulic fluids, such as may happen in an airplane, may also develop tunnel vision. Becoming ill while in an aircraft can cause temporary tunnel vision.

Certain diseases of the eye may also lead to tunnel vision. Retinitis pigmentosa, an inherited condition that may ultimately lead to blindness, can be a cause of tunnel vision. Typically, retinitis pigmentosa begins to show itself as night blindness, which then leads to tunnel vision and eventually to blindness. Some individuals with the disorder, however, do not go blind after developing tunnel vision.

Glaucoma, a disease affecting the optic nerve, can also cause tunnel vision. The pressure placed on the optic nerve causes the eye to lose retinal ganglion cells, which can eventually cause the patient to go blind. For some patients, tunnel vision may be experienced prior to blindness.

Use of hallucinogenic drugs can also cause damage to the brain and to the nerves, which can result in permanent or temporary tunnel vision. Extreme stress, such as that experienced during a panic attack, is another possible causes of temporary tunnel vision. Specific activities and sports can also cause temporary tunnel vision. Fighter pilots and acrobats may experience temporary tunnel vision from sustained high acceleration of one or more seconds. In this case, the person may also loss consciousness.

Exposure to oxygen at a pressure above 1.5 to two atmospheres can be toxic to the oxygen of the central nervous system. This most often occurs when diving. In addition to tunnel vision, this oxygen pressure can result in fatigue, dizziness, blindness, nausea, confusion, anxiety, and lack of coordination. When tunnel vision strikes a person engaged in an activity such as driving or piloting an aircraft, it can result in death, because the individual is unable to see properly.