Glossary
Searchable terminology from accessibility, web standards, and related fields.
68 results found in Conditions and Disabilities.
- Albinism (Oculocutaneous Albinism, Ocular Albinism)
- A group of inherited conditions characterized by reduced or absent melanin pigment production, affecting the skin, hair, and eyes. Ocular effects commonly include reduced visual acuity, nystagmus (inv…
- Amnesia (Memory Loss, Amnestic Disorder)
- A neurological condition characterised by the partial or complete inability to recall past experiences (retrograde amnesia) or to form new memories (anterograde amnesia). Amnesia results from damage t…
- Aniridia
- A rare congenital eye condition involving the partial or complete absence of the iris, often accompanied by reduced visual acuity, light sensitivity (photophobia), nystagmus, and sometimes glaucoma or…
- Anomalous Trichromat (Anomalous Trichromacy, Colour Anomaly)
- A person who has all three types of cone cells in the retina but one type has a shifted spectral sensitivity, causing altered colour perception that is less severe than dichromacy. Anomalous trichroma…
- Anterograde Amnesia
- A form of amnesia in which a person is unable to form new memories following the onset of the condition, while memories from before the injury or illness may remain largely intact. Anterograde amnesia…
- Asperger Syndrome (Asperger's Syndrome, AS, Asperger's Disorder)
- A neurodevelopmental condition previously classified as a distinct diagnosis within the autism spectrum, characterized by difficulties with social interaction and nonverbal communication, alongside re…
- Athetoid (Athetosis, Athetoid Movement)
- A type of involuntary movement characterised by slow, continuous, writhing motions, particularly affecting the hands, fingers, and face. Athetoid movements are commonly associated with athetoid cerebr…
- Athetoid Cerebral Palsy (Dyskinetic Cerebral Palsy, Athetosis)
- A form of cerebral palsy characterized by involuntary, uncontrolled, slow writhing movements, particularly affecting the hands, feet, arms, and legs, and sometimes the muscles of the face and tongue. …
- Autism Diagnostic Observation Schedule (ADOS, ADOS-2)
- A standardized diagnostic protocol for autism that uses structured and semi-structured social interaction tasks between an examiner and the person being assessed. First published in 1989 and designed …
- Autism Spectrum Disorder (ASD, Autism)
- A neurodevelopmental condition characterized by differences in social communication, sensory processing, and patterns of behavior or interests. Autism exists on a spectrum, meaning it presents differe…
- Becker Muscular Dystrophy (BMD)
- A genetic neuromuscular disorder caused by mutations in the dystrophin gene on the X chromosome, resulting in progressive muscle weakness and wasting. Becker Muscular Dystrophy is similar to Duchenne …
- Blue Cone Monochromatism (BCM, S-cone Monochromacy)
- A rare inherited vision condition in which only the blue (short-wavelength) cones function, resulting in severely reduced color vision, reduced visual acuity, photophobia, and nystagmus. Affected indi…
- Borderline Intellectual Functioning (BIF, borderline intellectual disability, slow learners)
- A condition describing individuals with IQ scores roughly between 70 and 85—above the diagnostic threshold for intellectual disability (IQ below 70) but below the neurotypical range. Representing abou…
- Challenging Behavior (Problem Behavior, Behaviors of Concern)
- Actions by individuals with intellectual or developmental disabilities that pose risks to themselves or others, or significantly interfere with daily activities and learning. In the context of autism,…
- Chiari Malformation (Arnold-Chiari Malformation)
- A structural condition in which brain tissue extends into the spinal canal, which can cause a range of neurological symptoms including headaches, balance issues, and vision problems such as blurred or…
- Co-contraction (Unintended Co-contraction, Muscle Co-activation)
- The simultaneous activation of antagonistic muscles — for example, the biceps and triceps firing at the same time. Some co-contraction is normal and useful for joint stability, but involuntary or exce…
- Co-morbidity (Comorbidity, Co-occurring Conditions, Multiple Disabilities)
- The simultaneous presence of two or more medical conditions or disabilities in a single individual. In accessibility contexts, co-morbidity is a critical design consideration because many users, parti…
- Cognitive Disability (Cognitive Impairment, Intellectual and Cognitive Disability)
- A broad category of disabilities affecting cognitive functions such as memory, attention, problem-solving, reading, language comprehension, and executive function. Cognitive disabilities can be develo…
- Cone Dystrophy (Cone-Rod Dystrophy)
- A group of inherited eye disorders that affect the cone cells in the retina, which are responsible for color vision, central vision, and visual acuity in well-lit conditions. People with cone dystroph…
- Dementia
- A group of progressive neurological conditions that affect memory, thinking, orientation, comprehension, language, and judgment. Alzheimer's disease is the most common form. Dementia significantly imp…