Visual field refers to the entire area that can be viewed on the side (peripherally) when the eyes are focused on a central point. The visual field test measures a person’s entire scope of vision (the central and the peripheral vision). With the visual field testing, blind spots in your vision can be detected.
During a visual field test you will sit in front of a concave dome and look at a target placed in the middle of the dome. Then you will press a button when you sees light flashes in your side vision. Responses help to determine if there is a defect in your visual field. It is often used to monitor conditions that may get worse with time. It is important that you are honest and cooperative, understand the instructions and complete the entire test in order to provide useful information.
The following conditions can be tested for and monitored by visual field testing:
- Screening and monitoring glaucoma
- Measuring the extent of retinal diseases
- Detecting problems with the optic nerve (tumors, poor circulation, injury and swelling of the nerve)
- Screening for lid droop
- Testing for toxicity from certain medications that can affect the central retina
- Testing for and diagnosing conditions that affect visual pathways (from the optic nerves to the occipital lobe of the brain).
With the high occurrence of visual impairments, visual field testing is useful for early detection of diseases of the retina (both central and peripheral), damage to the optic nerve, and eyelid conditions.