What is Visual Field Test
Visual Field Test is an eye exam that measures the entire scope of a person’s vision. This scope includes both the central and the peripheral (side) vision. The purpose of the exam is to detect any blind spots in the field of vision of the patient.
This eye exam is often used to detect damage to the optical nerve because of various eye disorders. In particular, the test is very effective in detecting damage caused by glaucoma. The test could also indicate presence of other eye related diseases such as central and peripheral retinal disease, damage to optical pathways and eyelid related diseases such as drooping.
This test is also used to evaluate the damage caused by stroke or brain tumors. The defects in visual field are often used to map out the location and size of tumors in brain.
The Process of Visual Field Test
There are several ways in which the test is conducted. Your doctor selects the types of exam based on the type of damage they wish to assess.
All types of visual field test are carried out one eye at a time. The other eye is covered to reduce the probability of errors in the results. The usual procedure is to test the right eye first, followed by the left eye. The patient is advices to look straight ahead so that the test could evaluate peripheral vision. The machine used for testing also measure the patient’s ability to hold a gaze at a fixed point.
The patient is asked to press a button as they detect light or movement in their side vision.