Perimeters & Accessories

While visual acuity tests our ability to distinguish fine lines of singular objects, visual field testing, or perimetry, takes our entire field of vision into consideration.

Now, perimetry is most commonly and accurately performed with perimeters, automated equipment that helps determine any deficiencies in patients’ field of vision.

Perhaps patients recall sitting in an eye doctor’s office, looking inside an instrument at a screen. While focusing his or her eyes on a target straight ahead, lights flash in different locations at varying levels of brightness. Whenever the patient sees this flash of light, he or she presses a button on a remote.

Throughout the exam, a computer records the location and timing of each flash and the patient’s corresponding—or lack of—response. Once the test is complete, a printout expresses any problematic areas of vision loss, where the patient did not see a flash of light.

These complications can be a result of:

• Glaucoma
• Brain tumors
• Pituitary disease
• Stroke
• Other neurological deficiencies

Additionally, perimetry testing can help monitor vision after diagnosis to ensure glaucoma treatment is effective in preventing further vision loss. More vision loss means optic nerve damage.