How to test your peripheral vision

Right now you are reading the words in this newspaper with both your eyes.

You have your eyes pointed at these words and all you are really aware of is the newspaper page that you see. Now, if someone were to sneak up behind you and slowly come around to your side, you would probably see the person move and know he or she was there.{{more}}

But how could you see someone off to the side of you if your eyes are looking straight at this page? It’s because you are using your peripheral (side vision) which accounts for a large percentage of your whole visual field. Your visual field is all you can see at one time without turning your head.

A defect in your peripheral vision is called a blind spot.

Did you know that you can test your peripheral vision by yourself? Please bear in mind that this is a rough test. You can only use it for gross defects in your field of vision. For subtler defects you will need to do a very sophisticated eye examination that tests thousands of different points on your retina to rule out certain conditions such as glaucoma, brain tumours, cataracts, retinal and optic nerve disease, among others

You are going to need a friend to help you do this test. You and your friend should sit facing each other, roughly two feet apart at eye level. You are going to need an object that you can hold at a slight distance from your hand, such as an eraser or pencil. Have your friend cover one eye and you cover one eye also. For example, your friend covers his or her right eye, and you cover your left eye.

Look directly into each others’ open eyes without moving. Now, with the pencil in your right hand, extend the eraser as far to your right as you can reach and slowly bring the eraser in towards you and your friend, keeping it on an imaginary line midway between the two of you. You will need to bend your elbow to do this. Both you and your friend should see the eraser come into view out of the corners of your eyes at about the same time.

Be sure it is the eraser you see and not the pencil. If one person sees the eraser much sooner than the other, the one who sees it last might have decreased peripheral vision, and should contact an eye doctor. A difference of four inches may be significant.

Now, do the technique again, but this time, bring the eraser in from your left side. Then, repeat the technique twice more. Bring the eraser down from over your head and up from your knees. Do the entire technique with opposite eyes.

Each time, both you and your friend should see the eraser at about the same time. This home peripheral vision test will pick up only very significant problems. For more accurate testing to find subtle effects in the visual field, see your eye doctor.

Dr Kenneth Onu is a resident Consultant Ophthalmologist at the Beachmont Eye Institute/Eyes R Us Send questions to: Beachmont@gmail.com
Tel: 784 456-1210