Glossary
Searchable terminology from accessibility, web standards, and related fields.
10 results found in Eye Conditions.
- 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…
- 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…
- Category 3 Blindness (ICD-10 H54 Category 3, WHO Category 3 Visual Impairment)
- A classification of severe visual impairment under the World Health Organization's ICD-10 coding for disorders of the visual system (H54). Category 3 covers blindness in which the better eye has prese…
- Hyperopia (Farsightedness, Long-Sightedness, Hypermetropia)
- A refractive error in which the eye focuses light behind the retina rather than on it, causing near objects to appear blurred while distant objects may remain relatively clear. Hyperopia occurs when t…
- Keratoconus
- A progressive eye condition in which the normally round cornea thins and bulges into a cone-like shape, causing irregular astigmatism and significant visual distortion that cannot be fully corrected w…
- Myopia (Nearsightedness, Short-Sightedness)
- A common refractive error in which the eye focuses light in front of the retina rather than on it, causing distant objects to appear blurred while near objects remain clear. Myopia occurs when the eye…
- Near Visual Acuity (NVA, Near Acuity)
- A measure of the eye's ability to resolve fine detail at a close distance, typically tested at 40 centimetres. Near visual acuity is particularly important for tasks involving reading, handheld device…
- Proliferative Diabetic Retinopathy (PDR)
- An advanced stage of diabetic retinopathy in which abnormal new blood vessels grow on the retina, causing bleeding, scarring, and progressive vision loss that can include blurred vision, floaters, dar…
- Pupil Diameter (Pupil Size, Aperture Size)
- The width of the opening in the iris through which light enters the eye, typically ranging from about 2mm in bright light to 8mm in darkness. Pupil diameter significantly affects visual quality becaus…
- Visual Aberration (Optical Aberration, Refractive Error)
- A deviation from ideal optical performance in the eye that causes images to appear blurred, distorted, or otherwise degraded on the retina. Visual aberrations include both lower-order aberrations (suc…