Periphery Vision

4 min read

A person's peripheral vision is what that person sees on the sides without directly looking to the side. In order to measure peripheral vision loss, a person should be looking straight ahead. If think your peripheral vision is blurry it is important to see an eye doctor as soon as possible. A disease called glaucoma causes peripheral vision loss. A doctor will use one of two tests to measure the periphery vision of a patient. These are called visual field tests. The visual field of a patient includes their central vision and the vision in their periphery.

Visual Field Test Confrontation

The first visual field test is called a confrontational visual field. This is done with a doctor and patient face to face across from each other. The patient covers one eye and looks at the doctor's nose. The doctor then holds up fingers on either side of the patient. While looking directly at the doctor, the patient is asked how many fingers are being held up. If the patient does not answer correctly then there is more of a concern for peripheral vision loss.

Humphrey Visual Field Test

The second test for peripheral vision is a more formal test called an automated visual field test. The most popular automated visual field test done in many doctor's offices is the Humphrey visual field test. The test takes about 5–8 minutes per eye

The patient places their chin into a bowl type machine and is asked to look straight ahead. The test is most accurate when the patient can maintain fixation on the central target. The patient is then given a hand held buzzer to press when they see a light is their peripheral vision. One eye is tested at a time, usually right then left. The eye that is not being tested is covered with an eye patch. When taking the visual field test, be sure to blink normally and concentrate on doing the test accurately. If the test shows that the patient was not looking straight ahead for the test, it could affect the accuracy of results. Your doctor may ask you to repeat the test if they feel that the results are not reliable.

What Is Glaucoma

Glaucoma is a disease of the optic nerve. When a patient has glaucoma their peripheral vision is at risk. Most patients with glaucoma do not even know that they have it. Peripheral vision loss in glaucoma tends to happen very slowly. There are usually no obvious signs or symptoms. It is best to see an ophthalmologist at regular intervals especially if you have risk factors for glaucoma. One big risk factor for glaucoma is race. Populations that are more at risk for glaucoma include persons of African American ancestery, Hispanics, and Asians. If someone in your family has glaucoma, you are also at higher risk for glaucoma. Having certain other diseases can also put you at risk for glaucoma. For example, patients who have sleep apnea are at higher risk for developing glaucoma. The peripheral vision loss that occurs in glaucoma is permanent and irreversible. It is extremely important to see your eye doctor to determine if you have glaucoma. Glaucome is not curable. But, glaucoma is very treatable. there are several medications that exist to treat glaucoma and most of these medications are well tolerated by most people.

Periphery Vision: Take Home Points

Testing of your periphery vision involves a visual field test. This can be done by a confrontational visual field or a more formal automated visual field. These tests are non invasive (no needles!) and take a few minutes per eye. Testing peripheral vision is especially important if you have risk factors for glaucoma. Glaucoma is a treatable but not curable eye disease. If it is untreated it can result in permanent peripheral vision loss. Glaucoma can also lead to total blindness and is one of the leading causes of vision loss in the world.

Sources:

Khoury, Johnny, M.; Donahue, Sean, P.; Lavin, Patric, J.; Tsai, James (1999). "Comparison of 24-2 and 30-2 Perimetry in Glaucomatous and Nonglaucomatous Optic Neuropathies".Journal of Neuro-Ophthalmology.19(2): 100–108.doi:10.1097/00041327-199906000-00004.PMID10380130

Ishiyama, Y.; Murata, H.; Mayama, C.; Asaoka, R. (11 November 2014)."An Objective Evaluation of Gaze Tracking in Humphrey Perimetry and the Relation With the Reproducibility of Visual Fields: A Pilot Study in Glaucoma".Investigative Ophthalmology & Visual Science.55(12): 8149–8152.doi:10.1167/iovs.14-15541.PMID25389198

McMonnies CW. Glaucoma history and risk factors. J Optom. 2017 Apr-Jun;10(2):71-78. doi: 10.1016/j.optom.2016.02.003. Epub 2016 Mar 23. PMID: 27025415; PMCID: PMC5383456.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5383456/

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