Seeing things out of the corner of your eye is a common phenomenon that can be attributed to the peripheral vision. The human visual system is designed to detect motion and changes in the environment, even in our peripheral vision, to help us stay alert and react quickly to potential threats. Here are a few reasons why you might perceive things in your peripheral vision that disappear when you look directly at them:
Sensitivity to motion: Our peripheral vision is more sensitive to detecting motion compared to fine details. When something moves or changes in your peripheral vision, it can grab your attention. However, when you turn your eyes to look directly at the object, it may no longer be moving or changing, making it more difficult to perceive.
Lower resolution and focus: The central part of our vision, known as the fovea, has higher resolution and is responsible for detailed perception. In contrast, the periphery has lower resolution and is better suited for detecting general shapes and movements. When you shift your gaze from the periphery to the central vision, the lack of detail and focus can cause objects or movements to appear less noticeable or even disappear.
Eye movement and attention: Our eyes are constantly making small, rapid movements called saccades, even when we are focusing on a specific object. These eye movements help us explore our surroundings and gather information. When you shift your attention to an object in your peripheral vision, your eyes may make a saccadic movement, which can cause the object to temporarily disappear from your direct line of sight.
Visual processing in the brain: The brain receives visual information from both the central and peripheral vision, but it processes and prioritizes information differently depending on the task at hand. When you consciously focus on an object, your brain may filter out irrelevant or less important visual stimuli from your peripheral vision, causing them to fade from your awareness.
In most cases, seeing things out of the corner of your eye is a normal part of visual perception. However, if you frequently experience persistent or disturbing visual phenomena, it may be worth discussing your symptoms with a healthcare professional or an optometrist to rule out any underlying eye conditions.