1. Visual perception - Definition
Visual perception refers to the process involved in the identification and recognition of visual information detected by the eyes and processed by different areas of the brain. (Dutton & Lueck, 2015). Visual perception is the ability to see, organize, and interpret information in the environment and give meaning, linguistically, and cognitively.
Visual perception is an essential day-to-day function involved in exploring visual information available in the environment since around 70-80% of the brain´s activity is dedicated to the processing of visual information. Without visual perception, a child/teen would not be able to make sense of words read in books, recognize common objects, perform eye-hand coordination necessary to manipulate objects, write, draw, recognize people´s faces, and recognize landmarks necessary for spatial orientation, and so forth.
2. Visual processing disorders
Visual processing disorders or visual perceptual disorders involve difficulties interpreting and understanding visual information, including the perception of movement, spatial relationships, faces, forms, and direction.
3. Causes of visual processing disorders
Visual processing disorders can result from injuries or dysfunctions of different areas of the brain as an effect of different medical conditions such as cerebral palsy, epilepsy, metabolic disorders, acquired or traumatic brain injuries, learning disabilities, etc. These disorders might cause difficulties in different grades and types of achieving daily life and educational activities. The child/teenager can encounter different types of visual processing disorders. Please find a short description of different perception functions in the section, "Perceptual functions".
4. Daily life and visual processing disorders
The practical manifestation of visual processing disorders is translated into the difficulty of finding details such as mistaking words with a similar beginning, struggle with learning based on visual information, not remembering places or settings that have been seen before or being familiar with, and so forth.
When one of the visual perceptual (visual processing) areas is impaired, the child can still find reading and writing strategies and organize and manage educational activities. Still, it might take a long time and a lot of cognitive effort that slows down the learning process or need specialty intervention and support.
5. Are visual processing disorders permanent?
Visual processing disorder is not a permanent condition, but early diagnosis is important for early intervention and providing personalized training and rehabilitation programmes. Visual processing disorder is a part of the sensory processing disorders that are accepted by the Diagnostic Classification of Mental Health and Developmental Disorders of Infancy and Early Childhood (DC:0-3R). The Diagnostic Classification is the first developmentally based system for diagnosing mental health and developmental disorders in infants and toddlers.
6. Visual processing disorders vs. visual impairment
Visual processing disorders is not a visual disability and do not occur only in children with visual disabilities or oculomotor diseases. Children with a full vision (visual acuity) of 20/20 or 6/6 and no visual field defects could also encounter visual perceptual difficulties.
7. Mechanisms of visual perception
The mechanisms of visual perception are the result of the contribution and “agreement” among the three main components of the visual system:
eyes, the receptor component of visual information
the optic nerve and optic tracts, the transmission pathways of visual information, and
different areas of the brain, responsible for the processing and interpretation of visual information.
The definitions and description of the concepts used in this section are based on several references that you can consult here.