| 释义 |
snow blindness
snow blindnessn. A usually temporary loss of vision and inflammation of the conjunctiva and cornea, caused by exposure of the eyes to bright sunlight and ultraviolet rays reflected from snow or ice.
snow′-blind′, snow′-blind′ed (-blīn′dĭd) adj.snow′ blind`ness
n. the usu. temporary blindness caused by the glare of reflected sunlight on snow. snow′-blind`, adj. Translationssnow blindness
snow blindness[′snō ‚blīnd·nəs] (medicine) A transient visual impairment and actinic keratoconjunctivitis caused by exposure of the eyes to ultraviolet rays reflected from snow. Also known as solar photophthalmia. snow blindness
blindness [blīnd´nes] lack or loss of ability to see (see vision). Legally, blindness is defined as less than 20/200 vision in the better eye with glasses (vision of 20/200 is the ability to see at 20 feet only what the normal eye can see at 200 feet). A person with 20° or less vision (pinhole vision) is also legally blind. In 2002, the number of people classified as legally blind in the United States was estimated at 10 million; millions more had severe visual impairments. The five leading causes of impaired vision and blindness in the United States are age-related macular degeneration, cataract, glaucoma, retinopathy" >diabetic retinopathy, and atrophy of the optic nerve" >optic nerve. Besides health care problems, issues related to employment, independent living, and literacy should all be considered when caring for patients who are blind. The American Foundation for the Blind is a resource center for information related to visual problems. They can be contacted by calling 1-800-232-5463 or consulting their web site at http://www.afb.org.blue blindness (blue-yellow blindness) popular names for imperfect perception of blue and yellow tints; see tritanopia and tetartanopia.color blindness color vision deficiency.complete color blindness vision" >monochromatic vision.day blindness hemeralopia.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°.night blindness see night blindness.object blindness (psychic blindness) visual agnosia.red blindness popular name for protanopia.red-green blindness (red-green color blindness) popular names 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 the glare of the sun upon snow.total color blindness vision" >monochromatic vision.yellow blindness popular name for tritanopia.snow blind·nesssevere photophobia secondary to ultraviolet keratoconjunctivitis.snow blindnessn. A usually temporary loss of vision and inflammation of the conjunctiva and cornea, caused by exposure of the eyes to bright sunlight and ultraviolet rays reflected from snow or ice.
snow′-blind′, snow′-blind′ed (-blīn′dĭd) adj.snow blind·ness (snō blīnd'nĕs) Severe photophobia secondary to ultraviolet keratoconjunctivitis. snow blindness The popular term for actinic keratopathy-damage to the outer layer of the corneas (the EPITHELIUM) from the effects of prolonged exposure to solar ultraviolet light. There is a temporary inability to keep the eyes open because the corneal nerves are painfully stimulated by the moving lids and there is tearing and BLEPHAROSPASM. If the eyes are kept shut the corneal epithelium regenerates in a day or two. |