A visual search is an exercise involving the visual center of the brain. It is designed to test a person’s visual sharpness and mental response time. A visual search involves locating a certain object, often in a field of similarly shaped and colored objects. It is often used as a diagnostic or therapeutic tool in vision testing. It also forms the basis for popular games and books usually designed for children, but is played by people of all ages.
A basic visual search is a common human activity. Most people routinely perform such searches dozens of times a day. Examples include locating a particular product on store shelves, recognizing a friend’s face in a group of strangers, or finding an item of clothing in a closet. What seems to be a simple process actually involves complex coordination of the eyes with various parts of the brain. This allows people to distinguish items based on color, position, and other factors.
Studies of brain activity have revealed which parts of the brain are involved in different aspects of a visual search. Consequently, such searches can be a diagnostic tool for medical personnel. If a patient has difficulty performing simple visual searches, it can be an indication of a brain disorder such as Alzheimer’s, an injury, or a lesion in the brain. Similar tests can reveal problems with the eye-brain relationship or within the eye itself. The test for color blindness involves a visual search, requiring the patient to recognize a shape within a larger pattern by color alone.
In a visual search, the subject is required to locate a single object or group of objects called a target. The target is placed amid other objects, called distractors. Increasing the number of distractors and their similarity to the target object makes visual searches more difficult. Another factor in such searches is reaction time: how long it takes the subject to locate the target item. For this reason, some visual searches have a time limit or otherwise base their results on the length of time the task requires.
Visual searches also form the basis for popular games, many designed for children and others for adults. Some involve locating an image disguised as a background detail in a drawing. Another visual search game is the word search, where players must find words concealed within a block of random letters. The Where’s Wally? books by Martin Handford challenged players to locate the title character amid large cartoon images containing hundreds of people. Where’s Wally?, known in the U.S. and Canada as Where’s Waldo?, became a cultural phenomenon in the 1990s, and the series remains popular in the 21st century.