While most people believe vision is just seeing 20/20, there is actually a lot more involved when it comes to our sight. Vision is a dynamic process that involves the input of light that is then processed into information and completed by some type of response, whether that be a thought and/or an action. Within the visual system there are two pathways, the central pathway and the peripheral pathway. Our central vision is the middle part of the visual field and is primarily concerned with identification or “What” objects are. While our peripheral vision is all that is visible outside the central area of focus and is primarily concerned with movement. This provides information for “Where am I/Where is it?” and enables visually guided movements such as pointing along with posture, balance, and movement.
Let’s say we are walking from house to house, trick-or-treating. Since our central visual system is what allows us to make important judgments like estimating distance and understanding details in the path ahead of us, we are using our central visual system in order to know where that next house with yummy candy is. While we are walking we notice something that causes us to turn our head. The object that we noticed was detected within our peripheral visual field, or side vision. Since details come from our central vision our reaction is to look in the direction of the object. Once the object is identified, we can determine if it’s something that is threatening, such as a scary monster coming towards us or if it is harmless, like a scarecrow. Once we have determined if it’s a prop or a scary monster we can decide on our next action.
Reading can be another good example of how we use our central and peripheral systems. As you are reading this right now you may notice that when you look directly at a word it is clear, but all the surrounding words are hard to make out. We are able to read due to the integration of our central and peripheral systems. The central system allows us to see the clear word we are looking at and our periphery is helping us locate and accurately move our eyes to the next word.
Be sure this Halloween to pay attention to your peripheral vision so you don’t get spooked!
-Nicole Ferreyros, Vision Therapist