Colours and Colour Vision

Background: Colorblind disability causes difficulties for people in daily life. Derived from the critical requirement to detect the patients in order to help prevent inappropriate careers, especially careers related to transportation, this research aim to determine the situations and the distributions of different types of visual disabilities. Materials: 1174 students (787 boys and 387 girls) including 2 groups: occupation group and transportation group were tested with ISHIHARA chromatic plates for colour vision deficiencies (CVD) (CVD iclude the total colour blindness, red- green blindness, red-blindness, green- blindness). The results are showed as follow: (i) Frequency of CVD boys among boy group is 4.70%; (ii) Frequency of CVD girls among girls group is 2.58%; (iii) In boy group, among 3 types of red- green blindness, the green-blindness has the higher frequency (3.18%) comparision with these ones of the red- green blindness and red-blindness. The total colour defiency was hardly; (iv) Frequency of CVD students among occupation group is 4.15%; (v) Frequency of CVD students among transportation group is 3.83%.

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Birds in the Dark: Complementary and Partial Information

10.1093/oso/9780199694532.003.0006 ◽

2017 ◽

Author(s):

Graham R. Martin

Keyword(s):

Annual Cycle ◽

Colour Vision ◽

Partial Information ◽

Night Time ◽

Light Levels ◽

Night Feeding ◽

Nocturnal Species ◽

Length Changes

Night-time poses exacting problems for vision, resolution inevitably falls and colour vision is not possible as light levels decrease to those of natural night time. Furthermore, light levels are highly variable depending upon whether there is moonlight, and night length changes dramatically in the annual cycle according to latitude. Few birds exploit the resources available at night. Those that do rely upon information received from vision complemented by information from other senses (hearing, olfaction, and touch), and upon highly specialized and restricted behaviours. However, many birds occasionally exploit night-time, e.g. during migration, arriving and departing from nests, and occasional night feeding. Some seabirds dive to such depths that they experience night-time light levels when foraging. Truly nocturnal species such as owls, kiwi, and oilbirds are highly sedentary, and this is essential to allow them to interpret correctly the partial information that is available to them.

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Myopia-26, the female-limited form of early-onset high myopia, occurring in a European family

Orphanet Journal of Rare Diseases ◽

10.1186/s13023-021-01673-z ◽

2021 ◽

Vol 16 (1) ◽

Author(s):

Noémi Széll ◽

Tamás Fehér ◽

Zoltán Maróti ◽

Tibor Kalmár ◽

Dóra Latinovics ◽

...

Keyword(s):

Middle Ages ◽

Early Onset ◽

Colour Vision ◽

High Myopia ◽

Field Testing ◽

Cone Dystrophy ◽

Ophthalmological Examination ◽

Whole Exome ◽

Caucasian Family ◽

Cone System

Abstract Background Female-limited early-onset high myopia, also called Myopia-26 is a rare monogenic disorder characterized by severe short sightedness starting in early childhood and progressing to blindness potentially by the middle ages. Despite the X-linked locus of the mutated ARR3 gene, the disease paradoxically affects females only, with males being asymptomatic carriers. Previously, this disease has only been observed in Asian families and has not gone through detailed investigation concerning collateral symptoms or pathogenesis. Results We found a large Hungarian family displaying female-limited early-onset high myopia. Whole exome sequencing of two individuals identified a novel nonsense mutation (c.214C>T, p.Arg72*) in the ARR3 gene. We carried out basic ophthalmological testing for 18 family members, as well as detailed ophthalmological examination (intraocular pressure, axial length, fundus appearance, optical coherence tomography, visual field- testing) as well as colour vision- and electrophysiology tests (standard and multifocal electroretinography, pattern electroretinography and visual evoked potentials) for eight individuals. Ophthalmological examinations did not reveal any signs of cone dystrophy as opposed to animal models. Electrophysiology and colour vision tests similarly did not evidence a general cone system alteration, rather a central macular dysfunction affecting both the inner and outer (postreceptoral and receptoral) retinal structures in all patients with ARR3 mutation. Conclusions This is the first description of a Caucasian family displaying Myopia-26. We present two hypotheses that could potentially explain the pathomechanism of this disease.

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