Try this simple test: while staring straight ahead, try to be aware of the objects to your left, right, above and below—all without moving your head and eyes.
Not as easy as it seems, is it? That's because your brain is accessing visual information outside your central field of view. It's this visual boundary that optometrists refer to as your peripheral vision.
What you might not know, however, is just how important peripheral vision is to your overall sight. In fact, it's a key way we see the world around us and is one of the largest portions of our visual field, accounting for over 100 of the 170 degrees that your field of view is capable of taking in.
Peripheral vision is about more than just seeing things out of the “corner of your eye.” It involves your retina, the thin layer of tissue located in the back of the eye that transmits visual images to the brain. This information is transmitted via receptor cells known as rods and cones. Rod cells are essential for seeing in dim light, but are unable to distinguish colour. Cone cells are concentrated in the centre of the retina and enable us to see bright lights and colour. Both these receptors help us make out objects in our peripheral vision, which explains why colours and shapes out of our direct field of view can be difficult to make out.
It's interesting to note that peripheral vision is much weaker in humans than in other species. This is because we don't have as many rods and cones as most animals. What's more, the way our peripheral vision works has changed a great deal as we've evolved. For primitive humans it would have been incredibly important to have peripheral vision to spot potential predators and other dangers, but some evolutionary biologists suspect our eyes may have evolved in such a way that our peripheral vision isn't quite as sharp as it once was.
Peripheral Vision Loss
Unfortunately, most people don't really think about their peripheral vision until they begin to lose it, a condition known as “tunnel vision.”
Symptoms of peripheral vision loss are often extremely subtle and hard to detect, even by someone suffering from the condition. The most common symptoms include difficulty seeing in dim light and trouble staying balanced while walking. While most eye care professionals believe that peripheral vision loss is linked to nerve damage, it can also be caused by glaucoma, injuries, strokes, concussions, and certain types of diseases.
If at any time you feel like you might be losing your peripheral vision, you should see an eye doctor immediately. They'll administer a visual field test to determine any blind spots you might have and what might be the potential cause. Unfortunately, treating peripheral vision loss can be extremely challenging, and in some cases the only option is to simply prevent the condition from worsening, which is why early diagnosis is so important.
Ultimately, the best way to ensure your peripheral vision is as strong as it can be is to maintain regular eye exams with your optometrist. Your eye doctor will be able to offer a clear picture when it comes to both your peripheral vision and the overall health of your eyes.
To get tested for peripheral vision loss, visit one of our eye care specialists at your nearest Visique location.