To understand peripheral vision, it helps to have a good idea of the whole process of sight, so here it is in simple terms.
What is the Central Vision Area?
The fovea centralis is the central angle of just a few degrees which is directed at what we are looking at. Fovea is Latin for pit, and the fovea centralis is full of cones and rods (specialised receptor cells) in the retina that enable us to see sharp detail and colour in bright light.
The retina is a light-sensitive area at the back of the eye. In front of this is the lens and front/centre of the lens is the pupil.
The macula is a small area in the centre of the retina that converts light into signals the brain can interpret and which through the wonders of biology we “see” as objects we can recognise and put a name to.
Outside The Central Vision Area – or on the Periphery
The concept of peripheral vision is not fully understood by many people in the general population, even though everyone uses expressions such as, “I saw it out of the corner of my eye”, which is basically what peripheral vision is.
The periphery of something is the outer edge. For instance, a suburb is an area on the outskirts (the periphery) of a city.
So, we have our field of vision, and peripheral vision makes up most of it, but it is not the parts that we are actually focusing on. When we are looking at something, our eyes are trained on it, directed at it. While we cannot see what is behind us, we can see (or at least be aware of) more than half of the 360 degrees around our head.
The fovea centralis (see above) is trained on what we want to look at and is full of rods and cones (as is the rest of the retina) which are picking up other things in the field of vision. Rods are like straight sticks, while cones are wide at one end and narrow at the other, just like ice cream cones or traffic cones.
What is Peripheral Vision Useful for?
While we are concentrating on what is in front of us, there may be other things going on that we need to be aware of. If we’re driving, for instance, we are taught to keep our eyes on the road, in the direction we’re heading in.
But there are other vehicles making movements that could affect us – alongside us or emerging from other roads and lanes. Peripheral vision gives us an idea of what is happening in these other areas, and our instincts tell us when we should turn our head and make one of these things the centre of our attention.
Peripheral vision performs the same function if, for instance, we are playing a team sport in which we need to be aware of what the opposing players are up to.
We don’t need to think about how our brain is receiving this information, as long as it is getting it, but if peripheral vision is damaged or deteriorating, it greatly affects our overall awareness and by extension our safety or competitive advantage. To learn more about peripheral vision, visit Microprism Vision.