When it comes to clear seeing, people rarely think of periphery. Yet periphery is an indispensable part of the way we humans see the world. In this section, we will try to shine some light onto why periphery should stay in the center of your attention.
VISION FIELD
Field of view is the angular extent of what can be seen with the eyes. Humans have general static horizontal field of view of up to about 200 degrees. However the majority of population rarely reaches such a wide angle of view, with some able to see only as little as 135 degrees.
The middle 120 degrees of the vision field provides an opportunity for the presence of binocular vision, which is the basis for 3D vision.
In addition, vertical field of vision for humans is about 50 degrees in the upper visual field and 70 degrees in the lower visual field.
The most simple way to divide the human field of vision is into the central field of view and the peripheral field of view.
CENTRAL FIELD OF VIEW
The central field of view is relatively narrow with the sharpest vision concentrated within only about a 2 degree angle. Clear vision is possible thanks to photoreceptors called cones, which are responsible for detecting light and seeing color. They are present in and around a small area of the retina called the macula. The strongest concentration of the cones can be found in the center of the macula, in a tiny spot called the fovea. The fovea is the only part of the retina that permits 100% visual acuity.
PERIPHERAL FIELD OF VIEW
There is a broad set of non-central points in the visual field that can still be seen, but not seen clearly. Those points are reachable with what is called the peripheral vision, the vision which occurs outside of the very center of gaze, and which is critical for one’s spatial orientation and awareness of their surroundings.
Peripheral vision is mostly dependent on visual receptors called rods, responsible for detecting movement and for seeing in the dark.
360° OF PERIPHERY
Peripheral vision allows you to stay aware of the world that is above you, below you and to both sides.
Inner periphery is present as well, however, unless you are looking into the distance, it is often replaced with the central vision.
HOW FAR CAN YOU SEE?
Horizontal peripheral vision has two levels (or sides), physical and sensorial:
PHYSICAL
Physical peripheral vision covers the field of view that is detectable by the eyes.
It is commonly divided into 3 parts, and named based on their distance from the point of focus. Near periphery (up to about 30°), Mid periphery (up to about 60°), and Far periphery (up to about 100°)
SENSORIAL
Beyond the point of what the eyes can detect exists the part of vision accessible via other senses. Athletes with highly developed peripheral vision and those trained in the art of seeing are strongly aware of the world that is out of reach of the eyes. They know where other people and objects are relative to themselves no matter where they stand, they can “see” what is behind them.
Overbound Clarity program focuses on the development of the physical peripheral vision. If your ability happens to go beyond that, consider it a bonus.
REASONS TO DEVELOP PERIPHERAL VISION
Seeing the periphery is as important for good vision as is visual acuity. Here are a few reasons why.
Overall health of the eyes
Through their different parts, your eyes are meant to detect and receive different signals. If some parts are absent (meaning inactive), the parts that remain have to work much harder to compensate for the missing pieces. They get tired easier and work less effectively. Just think of how much harder it is to carry a bucket full of water with just one finger, vs the whole hand.
Personal safety
Whether you walk, ride a bike or drive a car, peripheral vision helps you with knowing what the terrain looks like by your feet, where you are on the road or who is to your side.
Faster reading
You read within your central vision, not within your periphery. However, peripheral vision provides a preview of what is coming up to the fovea, which makes it easier for a fluent movement of focus from one spot to the next. That, at the end, results in faster reading without strain.