Visual attention is the process in which the human brain decides which details within a person's field of vision are important and should be focused upon, and which are largely ignored and filtered into the background. Information, such as environments with low light levels, are often increased in detail by the brain to ensure the information required is processed effectively. If background information was not filtered by attention determining areas of the brain, a person would be overwhelmed by the sheer amount of visual information the eyes pick up.
The process by which the brain filters information and determines which details are required at a given moment is not fully understood by researchers; different models of how information is processed in the brain have been created, but none are proven. Visual attention is important in the everyday life of humans because without the ability to filter information, tasks such as driving would prove almost impossible to complete safely. By placing the attention of the brain onto required details, such as speed limit signs, potentially dangerous situations can be avoided as the brain highlights important details.
Processing information to ensure visual attention is paid to important details can take the form of behavioral and active brain activity. Details required to ensure a person completes a behavior or specific task successfully are passed through the retina of the eye to the brain, with information not required to complete the activity given less attention than the required details. The brain can also actively direct visual attention towards specific details observed in everyday life, Throughout the day, each person decides which information is required to achieve his or her goals and maintain his or her safety and health from observed information.
The exact moment when details are processed by the brain and irrelevant information is filtered from what is seen has been described in numerous psychological theories. In some research studies, claims have been made for the filtering of information taking place directly after being seen before details are fully processed by the brain. Other theories claim the process of paying attention to details is completed after all the information within the field of vision is processed by the brain, resulting in a selection being made over which details are important or irrelevant at that moment.
Determining which details are require visual attention is important in situations where light levels are low and people find it difficult to see. Entering a dark environment after being in a bright one requires a person's brain to lift darkened details into a higher contrast to allow the person to find important information. Research into visual attention includes trying to find a better understanding of how the eyes and brain interact.