Sitting in front of a concave dome, a computer-driven program flashes small lights at different locations within the dome's surface, and you press a button when you see the small lights in your peripheral vision. Your responses are compared to age-matched controls to determine the presence of defects within the visual field. The test will detect any loss of peripheral vision and provide a map of that loss which will be helpful in diagnosing the cause.

Normal Results
The peripheral vision is normal in extent.

What Abnormal Results Mean
Abnormal results may indicate diseases or central nervous system problems such as tumors that damage or compress the parts of the brain that deal with vision. Other diseases that may affect the visual field of the eye include diabetes, hyperthyroidism (a condition where the thyroid produces an excess of hormones), hypertension, diseases of the pituitary gland, and multiple sclerosis.