a·blep·si·a ( -bl p s -) or a·blep·sy (-blps)n. Lack of sight; blindness. |
ablepsia
[əblep′sē·ə]
Etymology: Gk, a + blepein, not to see
the condition of being blind. Also called ablepsy.
ablepsia
blindness.
blindness
1. Inability to see. 2. Absence or severe loss of vision so as to be unable to perform any work for which eyesight is essential. The World Health Organization (WHO) defines blindness as the best corrected visual acuity of 3/60 (20/400) or less, in the better eye. Syn. ablepsia; ablepsy; amaurosis.
blue blindness See tritanopia.
colour blindness Sometimes this term is incorrectly used to cover all forms of colour vision deficiency, however mild or severe. See achromatopsia; defective colour vision; deuteranopia; monochromat; protanopia; tritanopia.
congenital stationary night blindness Night blindness (nyctalopia) inherited as either autosomal dominant with non-progressive nyctalopia but normal daylight visual acuity and visual fields and presumed to be due to a defect in neural transmission between the rods and the bipolars in the retina, or autosomal recessive or X-linked with congenital nyctalopia, myopia, nystagmus and reduced visual acuity. See Oguchi's disease; fundus albipunctatus; hemeralopia; retinitis pigmentosa.
cortical blindness Loss of vision due to lesions in the areas of both occipital lobes of the brain associated with visual functions. It may result from trauma or from a vascular disease (e.g. a circulatory occlusion caused by a stroke). A lesion in one occipital lobe may result in homonymous hemianopia, often with macular sparing.
day blindness See hemeralopia.
eclipse blindness Partial or complete loss of central vision due to a foveal lesion caused by fixating the sun without adequate eye protection. This condition is caused mainly by the infrared radiations from the sun. See actinic.
flash blindness See actinic keratoconjunctivitis.
green blindness See deuteranopia.
hysterical blindness Blindness associated with an emotional shock, which occurs without a physical or organic cause. The patient has normal blink and pupillary responses and the fundus appears normal. A placebo therapy and/or psychological counselling may be required.
legal blindness The definition varies from country to country. In the UK it is equal to either 3/60 (20/400) or worse; or 6/60 (20/200) or worse, with markedly restricted fields.
motion blindness A very rare condition in which a patient is unable to process information about motion, although other visual functions are unimpaired. This is believed to be the result of damage to the middle temporal cortex (V5). See visual association areas.
night blindness See hemeralopia.
perceptual blindness See agnosia.
red blindness See protanopia.
river blindness See onchocerciasis.
snow blindness See actinic keratoconjunctivitis.
word blindness See alexia.
blue blindness See tritanopia.
colour blindness Sometimes this term is incorrectly used to cover all forms of colour vision deficiency, however mild or severe. See achromatopsia; defective colour vision; deuteranopia; monochromat; protanopia; tritanopia.
congenital stationary night blindness Night blindness (nyctalopia) inherited as either autosomal dominant with non-progressive nyctalopia but normal daylight visual acuity and visual fields and presumed to be due to a defect in neural transmission between the rods and the bipolars in the retina, or autosomal recessive or X-linked with congenital nyctalopia, myopia, nystagmus and reduced visual acuity. See Oguchi's disease; fundus albipunctatus; hemeralopia; retinitis pigmentosa.
cortical blindness Loss of vision due to lesions in the areas of both occipital lobes of the brain associated with visual functions. It may result from trauma or from a vascular disease (e.g. a circulatory occlusion caused by a stroke). A lesion in one occipital lobe may result in homonymous hemianopia, often with macular sparing.
day blindness See hemeralopia.
eclipse blindness Partial or complete loss of central vision due to a foveal lesion caused by fixating the sun without adequate eye protection. This condition is caused mainly by the infrared radiations from the sun. See actinic.
flash blindness See actinic keratoconjunctivitis.
green blindness See deuteranopia.
hysterical blindness Blindness associated with an emotional shock, which occurs without a physical or organic cause. The patient has normal blink and pupillary responses and the fundus appears normal. A placebo therapy and/or psychological counselling may be required.
legal blindness The definition varies from country to country. In the UK it is equal to either 3/60 (20/400) or worse; or 6/60 (20/200) or worse, with markedly restricted fields.
motion blindness A very rare condition in which a patient is unable to process information about motion, although other visual functions are unimpaired. This is believed to be the result of damage to the middle temporal cortex (V5). See visual association areas.
night blindness See hemeralopia.
perceptual blindness See agnosia.
red blindness See protanopia.
river blindness See onchocerciasis.
snow blindness See actinic keratoconjunctivitis.
word blindness See alexia.
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