FDT – (Frequency-doubling technology) was developed as a fast, effective way to detect visual field loss. The FDT is the ideal visual field screening device because it only 40 seconds per eye. This quick and easy test is preformed on all patients during all comprehensive eye exams.
The Humphrey Threshold Visual Field is a special automated procedure used to perform perimetry, a test that measures the entire area of peripheral vision that can be seen while the eye is focused on a central point. During this test, lights of varying intensities appear in different parts of the visual field while the patient's eye is focused on a certain spot. The perception of these lights is charted and then compared to results of a healthy eye at the same age of the patient in order to determine if any damage has occurred. This procedure is performed quickly and easily in about 15 minutes, and is effective in diagnosing and monitoring the progress of glaucoma. .
Patients with glaucoma will often undergo this test on a regular basis in order to determine how quickly the disease is progressing. The Humphrey Visual Field test can also be used to detect conditions within the optic nerve of the eye, and certain neurological conditions as well.