Also found in: Thesaurus, Medical, Encyclopedia, Wikipedia.
Related to hemeralopia: nyctalopia


A visual defect characterized by the inability to see as clearly in bright light as in dim light.

[New Latin hēmeralōpia, from Greek hēmeralōps, suffering from hemeralopia : hēmera, day + alaos, blind + ōps, eye; see nyctalopia.]

hem′er·a·lop′ic (-lŏp′ĭk) adj.


(Pathology) inability to see clearly in bright light. Nontechnical name: day blindness Compare nyctalopia
[C18: New Latin, from Greek hēmeralōps, from hēmera day + alaos blind + ōps eye]
hemeralopic adj


(ˌhɛm ər əˈloʊ pi ə)

a condition in which vision is normal in the night or in dim light but is abnormally poor or wholly absent in the day or in bright light.
[1700–10; < Greek hēmeralōp-, s. of hēmerálōps suffering from day blindness (hēmér(a) day + ala(ós) blind + -ōps having eyes of the kind specified; see Cyclops) + -ia; compare -opia]
hem`er•a•lop′ic (-ˈlɒp ɪk) adj.


a condition of the eyes in which the sufferer can see clearly at night but has impaired vision during the day; day blindness.
See also: Eyes
the loss of sight in daylight. — hemeralopic, adj.
See also: Blindness
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.hemeralopia - inability to see clearly in bright light
vision defect, visual defect, visual disorder, visual impairment - impairment of the sense of sight
References in periodicals archive ?
Cone dystrophy is a slowly progressive, diffuse photoreceptor dystrophy that presents as hemeralopia, reduced visual acuity, and nystagmus associated with macular cone photoreceptor and retinal pigment epithelium (RPE) atrophy [1-6].
During two years study, 31 cases of progressive retinal atrophy (PRA) were recorded in dogs with typical history of initial nyctalopia followed by hemeralopia. Out of 31 PRA suspected dogs, eight dogs (26%) were from the age group of 1-5 years, 15 (48%) 6-10 years and the rest (26%) 11-15 years.
From the two droughts that occurred at the end of the 19th century and those throughout the 20th century, there were registers of outbreaks and epidemics for the following diseases: daytime blindness (hemeralopia), trachoma, cholera, diarrhea, dysentery, typhus, paratyphoid, yellow fever, smallpox, bubonic plague, leishmaniasis and influenza.