Visual Field Test
The visual field (or field of vision) includes everything your eyes perceive around them. When you are driving or walking down the street, it allows you to see any moving objects coming from a distance. Even when you look straight ahead, your retinas discern some of what is happening around them. Slow reactions when driving may also suggest a weak visual field. To evaluate yours, take the test!
How to carry out the test
To perform this test, all you need is a pencil! This first step will give you an idea of how much your retina sees when you are looking at a specific point in front of you.
Step 1: Take the pencil in your right hand and hold it out directly in front of you. Cover your left eye with your free hand and stare at the horizon.
Step 2: Slowly move the pencil to the right, keeping your arm straight. Your eye should continue to look straight ahead.
When the pencil no longer appears in your field of vision, it is time to stop.
Step 3: Repeat on the other side with your left eye closed. With your right arm, move the pencil to the left until it is no longer in your field of vision.
Then do the same for the left eye (this time with your right eye closed).
Of course, you will not be able to see the pencil clearly while looking at the horizon. You will perceive it as a moving shape and not as an object with precise contours.
A different result on each side
Your eyes are able to perceive their surroundings up to a certain angle. During the test, the pencil gradually moved out of your field of vision. The angle made by your arm to the right, then to the left, represented the limits of your field of vision. Do the exercise for each eye.
Please note that the visual field of your right eye is not the same on the right and left sides. If your visual field is normal, the angle should reach 90° on the right side and 60° on the left side (in relation to the point you are looking at in the distance, straight ahead).
The object responsible for this great mystery is none other than your nose! It limits the field of vision of your right eye due to its position on the left of this eye. The same applies, but the other way around, to the left eye.
What is next?
Taking an online visual field test can signal certain visual weaknesses. However, this is not a real ophthalmological test supervised by a professional. It is therefore impossible to make a diagnosis after completing the test.
If the pencil disappeared from your field of vision before 90° and 60°, it is best to make an appointment with a Visilab optician. They will give you a more thorough eye examination and detect any defects.
This is important also because when driving on the road, a reduced field of vision makes it impossible to anticipate the arrival of certain moving objects (pedestrians, cars, cyclists, etc.).
Did you know?
Before the age of 8, a child’s visual field is more limited than that of an adult. In everyday life, children mostly see what is in front of them. When they are near a road, they need 4 seconds to notice that a car is moving, compared to 1/7th of a second for adults!
Another danger? Children need fixed points of reference when they are moving around. They are also unable to estimate the time it takes for cars to approach, as they have trouble realising their distance and speed. In contrast, an adult needs no cues to immediately see moving objects and people.
Given that children are too small to be seen and too small to distinguish signs or see past obstacles, they are at a disadvantage when walking in the street. The difference in their perceptual system means that they are unable to process and anticipate all the dangers of the road. Dangers that they are all the more likely to forget if emotions are involved. For example, if they go running after a ball, or they are trying to reach a friend on the other side of the road.