Visual perception

Visual perception is the ability to interpret the surrounding environment using light in the visible spectrum reflected by the objects in the environment. This is different from visual acuity, which refers to how clearly a person sees (for example "20/20 vision"). A person can have problems with visual perceptual processing even if he/she has 20/20 vision.

The resulting perception is also known as eyesight, sight, or vision (adjectival form: visual, optical, or ocular). The various physiological components involved in vision are referred to collectively as the visual system, and are the focus of much research in linguistics, psychology, cognitive science, neuroscience, and molecular biology, collectively referred to as vision science.

Visual system

The visual system in humans allows individuals to assimilate information from their surroundings. The act of seeing starts when the cornea and then the lens of the eye focuses light from its surroundings onto a light-sensitive membrane in the back of the eye, called the retina. The retina is actually part of the brain that is isolated to serve as a transducer for the conversion of patterns of light into neuronal signals. The lens of the eye focuses light on the photoreceptive cells of the retina, which detect the photons of light and respond by producing neural impulses. These signals are processed in a hierarchical fashion by different parts of the brain, from the retina upstream to central ganglia in the brain.

Visual perception and the brain

Visual perception and the brain are part of the larger field of vision science, which includes all the physiological and psychological processes of sight. Vision science also includes the methods of studying perception, such as by observing behavior or by neuroimaging techniques.

Visual disorders

There are many types of visual disorders, including refractive error, cataract, glaucoma, age-related macular degeneration, diabetic retinopathy, and amblyopia. These disorders can affect visual perception and can cause a variety of symptoms, including blurred vision, double vision, halos around lights, and loss of vision.

See also

• Optical illusion
• Visual perception and the brain
• Visual disorders
• Visual system

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  Diagram of the ventral and dorsal streams in visual processing
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  Illustration of the line of sight from the eye
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  Visual perception over a two-second interval
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  Visual perception