blindness (redirected from Appaloosa night blindness)

blindness /blind·ness/ (blind´nes) lack or loss of ability to see; lack of perception of visual stimuli.

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blue blindness , blue-yellow blindness popular names for imperfect perception of blue and yellow tints; see tritanopia and tetartanopia .

color blindness 

1. popular name for color vision deficiency.

2. see monochromatic vision.

complete color blindness  monochromatic vision.

day blindness  hemeralopia.

flight blindness  amaurosis fugax due to high centrifugal forces encountered in aviation.

green blindness  imperfect perception of green tints; see deuteranopia and protanopia.

legal blindness  that defined by law, usually, maximal visual acuity in the better eye after correction of 20/200 with a total diameter of the visual field in that eye of 20 degrees.

letter blindness  alexia characterized by inability to recognize individual letters.

music blindness  musical alexia.

night blindness  failure or imperfection of vision at night or in dim light.

object blindness , psychic blindness visual agnosia.

red blindness  popular name for protanopia.

red-green blindness  popular name for any imperfect perception of red and green tints, including all the most common types of color vision deficiency. See deuteranomaly, deuteranopia, protanomaly, and protanopia.

snow blindness  dimness of vision, usually temporary, due to glare of sun upon snow.

text blindness  alexia.

total color blindness  monochromatic vision.

word blindness  alexia.

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blindness

lack or loss of ability to see. Diagnosed in an animal on the absence of a menace reflex, walking into obstructions and failure to indicate awareness of a soundless movement in its visual field, e.g. a falling cotton ball or feather.

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Appaloosa night blindness

see appaloosa.

bright blindness

toxic retinopathy in sheep grazing bracken; characterized by blindness, dilated pupils, poor pupillary light reflex, retinal degeneration.

central blindness

due to a lesion of the optic cortex; the pupillary light reflex still functions. Called also cortical blindness.

cortical blindness

see central blindness (above).

day blindness

defective vision in bright light. See also hemeralopia.

inherited congenital blindness

occurs in a number of breeds of cattle in which there are several defects in the eyes including irideremia, microphakia, ectopia lentis and cataract.

night blindness

failure or imperfection of vision in conditions of diminished illumination; a characteristic of progressive retinal atrophy.

peripheral blindness

blindness due to a lesion in the optical apparatus peripheral to the optical cortex, including lesions in the optic chiasma, optic nerve, retina, anterior and posterior chambers, lens and cornea. With the exception of obvious lesions in the eyeball this is characterized by dilatation of the pupil and absence of the pupillary light reflex.

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blindness An inability to see effectively. See Blue color blindness, Legal blindness, Night blindness, Occupational blindness, Snowblindness, Transient monocular blindness.