When you are looking straight ahead at something, that object lies within your central field of vision. While still looking at the object, you are probably able to detect other things to the left, right, top, and bottom. This ability to see things outside of your central field of vision is known as peripheral vision. Peripheral vision allows us to detect people entering the room, cars approaching, objects we may trip on while walking, and many other important things that we usually do not even think about.

Peripheral vision actually makes up the majority of our vision field. While your central field of vision is about 70 degrees, your peripheral vision is nearly 100 degrees.

Peripheral vision loss

Loss of peripheral vision can be surprisingly difficult to notice – even when it is happening to you! This type of vision loss tends to occur gradually as a symptom of other medical issues. The most common causes of peripheral vision loss are glaucoma, nerve damage, eye strokes, concussion, or a detached retina.

It is important to note that once peripheral vision has been lost, it cannot be regained. For this reason, those who are at a higher risk for developing peripheral vision loss should take care to prevent this loss. For example, if you are prescribed eye drops to manage eye pressure due to glaucoma it is very important not to be careless and skip the prescribed drops.

Retinal detachment 

Although peripheral vision loss usually happens gradually, this is not the case with vision loss due to retinal detachment. In the case of retinal detachment, the peripheral vision loss will happen suddenly. It is also characterized by sudden flashes of light in peripheral vision. If you experience a sudden loss of peripheral vision or flashing light in peripheral vision you should seek medical attention immediately, as a detached retina is a medical emergency and requires immediate treatment.

Peripheral vision test

A peripheral vision test is a standard part of a comprehensive eye exam. There are several variations of the test, but all involve looking straight ahead at a fixed object while images or lights appear outside of your central field of vision at various points to test your ability to detect them.

If you have glaucoma or another eye condition your eye care professional may administer peripheral vision tests more frequently to monitor peripheral vision loss.

Peripheral vision loss treatment

Once peripheral vision has been lost, there is not much that can be done to regain it.  The most effective “treatment” is simply prevention. Some types of peripheral vision loss can be treated with special eyeglass lenses called prism lenses, however this is not an effective treatment for all peripheral vision loss.

If you are concerned that you may have peripheral vision loss, make an appointment with your eye care professional to be tested.