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Golovin–Sivtsev Table
The Golovin–Sivtsev table () is a standardized table for testing visual acuity, which was developed in 1923 by Soviet ophthalmologists Sergei Golovin and D. A. Sivtsev. In the USSR, it was the most common table of its kind, and its use is still widespread in several post-Soviet states. The table consists of two parts with 12 rows each, representing visual acuity values between 0.1 and 2.0. — that website as a whole doesn't seem to be reliable, but it seems to present reliable information on Golovin-Sivtsev table dimensions The left part consists of series of the Cyrillic
The Cyrillic script ( ) is a writing system used for various languages acro ...
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Visual Acuity
Visual acuity (VA) commonly refers to the clarity of visual perception, vision, but technically rates an animal's ability to recognize small details with precision. Visual acuity depends on optical and neural factors. Optical factors of the eye influence the sharpness of an image on its retina. Neural factors include the health and functioning of the retina, of the neural pathways to the brain, and of the interpretative faculty of the brain. The most commonly referred-to visual acuity is ''distance acuity'' or ''far acuity'' (e.g., "20/20 vision"), which describes someone's ability to recognize small details at a far distance. This ability is compromised in people with myopia, also known as short-sightedness or near-sightedness. Another visual acuity is ''Near visual acuity, near acuity'', which describes someone's ability to recognize small details at a near distance. This ability is compromised in people with hyperopia, also known as long-sightedness or far-sightedness. A com ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ophthalmologist
Ophthalmology (, ) is the branch of medicine that deals with the diagnosis, treatment, and surgery of eye diseases and disorders. An ophthalmologist is a physician who undergoes subspecialty training in medical and surgical eye care. Following a medical degree, a doctor specialising in ophthalmology must pursue additional postgraduate residency training specific to that field. In the United States, following graduation from medical school, one must complete a four-year residency in ophthalmology to become an ophthalmologist. Following residency, additional specialty training (or fellowship) may be sought in a particular aspect of eye pathology. Ophthalmologists prescribe medications to treat ailments, such as eye diseases, implement laser therapy, and perform surgery when needed. Ophthalmologists provide both primary and specialty eye care—medical and surgical. Most ophthalmologists participate in academic research on eye diseases at some point in their training and many incl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
USSR
The Union of Soviet Socialist Republics. (USSR), commonly known as the Soviet Union, was a List of former transcontinental countries#Since 1700, transcontinental country that spanned much of Eurasia from 1922 until Dissolution of the Soviet Union, it dissolved in 1991. During its existence, it was the list of countries and dependencies by area, largest country by area, extending across Time in Russia, eleven time zones and sharing Geography of the Soviet Union#Borders and neighbors, borders with twelve countries, and the List of countries and dependencies by population, third-most populous country. An overall successor to the Russian Empire, it was nominally organized as a federal union of Republics of the Soviet Union, national republics, the largest and most populous of which was the Russian SFSR. In practice, Government of the Soviet Union, its government and Economy of the Soviet Union, economy were Soviet-type economic planning, highly centralized. As a one-party state go ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyrillic
The Cyrillic script ( ) is a writing system used for various languages across Eurasia. It is the designated national script in various Slavic, Turkic, Mongolic, Uralic, Caucasian and Iranic-speaking countries in Southeastern Europe, Eastern Europe, the Caucasus, Central Asia, North Asia, and East Asia, and used by many other minority languages. , around 250 million people in Eurasia use Cyrillic as the official script for their national languages, with Russia accounting for about half of them. With the accession of Bulgaria to the European Union on 1 January 2007, Cyrillic became the third official script of the European Union, following the Latin and Greek alphabets. The Early Cyrillic alphabet was developed during the 9th century AD at the Preslav Literary School in the First Bulgarian Empire during the reign of Tsar Simeon I the Great, probably by the disciples of the two Byzantine brothers Cyril and Methodius, who had previously created the Gl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sha (Cyrillic)
Sha, alternatively transliterated Ša (Ш ш; italics: ) is a letter of the Glagolitic and Cyrillic scripts. It commonly represents the voiceless postalveolar fricative , like the pronunciation of sh in "ship". More precisely, the sound in Russian denoted by ш is often falsely transcribed as a palatoalveolar fricative, but is actually a voiceless retroflex fricative . It is used in every variation of the Cyrillic alphabet for Slavic and non-Slavic languages. In English, Sha is romanized as sh or as š, the latter being the equivalent letter in the Latin alphabets of Czech, Slovak, Slovene, Serbo-Croatian, Latvian and Lithuanian. History Sha has its earliest origins in Phoenician Shin and is possibly linked closely to Shin's Greek equivalent: Sigma (Σ, σ, ς). (The similar form of the modern Hebrew Shin (ש), which is probably where the Cyrillic letter was actually derived from, derives from the same Proto-Canaanite source). Sha already possessed its current ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Be (Cyrillic)
Be (Б б; italics: ) is a letter of the Cyrillic script. It commonly represents the voiced bilabial plosive , like the English pronunciation of in "ball". It should not be confused with the Ve (Cyrillic), Cyrillic letter Ve (В в), which is shaped like Latin capital letter B but represents the voiced labiodental fricative or the voiced bilabial fricative . The Cyrillic letter Б (Be) is romanized using the Latin letter . History The Cyrillic letters Be and Ve (Cyrillic), Ve (В в) were both derived from the Greek letter Beta (Β β). In the Early Cyrillic alphabet the name of the letter Be was (''buky''/), meaning "letter". In the Cyrillic numerals, Cyrillic numeral system, the letter Be had no numeric value because the letter Ve inherited the Greek letter Beta's numeric value. Form The Russian small letter (be) is similar (but not identical) in shape to the 6, digit 6. Its lowercase form also somewhat resembles a lowercase letter B ("b"), the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Em (Cyrillic)
Em (М м; italics: ) is a letter of the Cyrillic script The Cyrillic script ( ) is a writing system used for various languages across Eurasia. It is the designated national script in various Slavic languages, Slavic, Turkic languages, Turkic, Mongolic languages, Mongolic, Uralic languages, Uralic, C .... Em commonly represents the bilabial nasal consonant , like the pronunciation of in "him". Common Glagolitic script is "Ⰿ and Ⱞ" It is derived from the Greek letter Mu (Μ μ). Form The capital Cyrillic letter Em (М м) looks the same as the capital Latin letter M (M m) but, as with most Cyrillic letters, the lowercase form is simply a smaller version of the uppercase letter. Usage As used in the alphabets of various languages, Em represents the following sounds: * bilabial nasal consonant , like the pronunciation of in "him" or meet * palatalized bilabial nasal consonant The pronunciations shown in the table are the primary ones for each language; for det ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
En (Cyrillic)
En (Н н; italics: ) is a letter of the Cyrillic script. It commonly represents the dental nasal consonant , like the pronunciation of in "neat". And it can be palatized like in the pair of hard and soft consonant for the word: 'wife' and 'wife's'. Glyph The capital Cyrillic letter En looks the same as the capitals Greek letter Eta (Η η) and Latin letter H. As with most Cyrillic letters, the lowercase form is simply a smaller version of the uppercase. However, in modern Church Slavonic publications, the old N-shaped form is still often used. It should not be confused with the letter И (similar to a mirrored shape of the Latin letter N): * The cursive of the capital letter is similar to the English model Copperplate script, with a modification: the line between the two columns is a rising diagonal, exactly as in letter И. And the minuscule, use quite the same ductus (without the loops), leading generally to a rising diagonal too. * In some handwritten and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ka (Cyrillic)
Ka (К к; italics: ''К к'') is a letter of the Cyrillic script. It commonly represents the voiceless velar plosive /k/, like the pronunciation of ⟨k⟩ in "king" or "kick". History The Cyrillic letter Ka was derived from the Kappa (letter), Greek letter Kappa (Κ κ). In the Early Cyrillic alphabet its name was (''kako''), meaning "as". In the Cyrillic numerals, Cyrillic numeral system, Ka had a value of 20. Form The Cyrillic letter Ka Homoglyph, looks very similar, and corresponds to the K, Latin letter K. In many fonts, Cyrillic Ka is differentiated from its Latin and Greek counterparts by drawing one or both of its diagonal spurs with curved instead of straight. Also in some fonts the lowercase form of Ka has the vertical bar elongated above x-height, resembling the Latin lowercase k. Usage In Russian language, Russian, the letter Ka represents the plain voiceless velar plosive or the palatalized one ; for example, the word "" (''"short"'') contains b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yery
Yeru or Eru (Ы ы; italics: ''Ы'' ''ы''), usually called Y in modern Russian language, Russian or Yery or Ery historically and in modern Church Slavonic, is a letter in the Cyrillic script. It represents the close central unrounded vowel (more rear or upper than i) after non-palatalised (hard) consonants in the Belarusian alphabet, Belarusian and Russian alphabets. The letter is usually romanisation of Russian, romanised , such that the family name is usually written Krylov (other), Krylov in English language, English and most other West European languages. That spelling matches the Polish alphabet, Latin alphabet used for Polish language, Polish, whose letter represents the same sound. Similarly, is used for in the Cyrillic transcriptions of Polish, cyrillisation of Polish, such that the name appears as in Russian. Note, however, that the letter also appears in romanisation of other Russian letters both in isolation (such as , ) and as part of di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
I (Cyrillic)
I (И и; italics: ''И и'' or ; italics: ) is a letter used in almost all modern Cyrillic alphabets with the exception of Belarusian alphabet, Belarusian. It commonly represents either the close front unrounded vowel (e.g., in Russian), like the pronunciation of in "machine", or the near-close near-front unrounded vowel , (e.g., in Ukrainian), like the pronunciation of in "bin". History Because the Cyrillic letter И was derived from the Eta (letter), Greek letter Eta (Ηη), the Cyrillic had the shape of up to the 13th century. The name of the Cyrillic letter И in the Early Cyrillic alphabet was (''iže''), meaning "which". In the Cyrillic numerals, Cyrillic numeral system, the Cyrillic letter И had a value of 8, corresponding to the Greek letter Eta (Eta, Ηη). In the Early Cyrillic alphabet, like in the Greek alphabet of the time (see Iotacism), there was little or no distinction between the letter / and the letter , the latter of which was deri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Landolt C
The Landolt C, also known as a Landolt ring, Landolt broken ring, or Japanese vision test, is an optotype—a standardized symbol used for testing vision. It was developed by the Swiss-born ophthalmologist Edmund Landolt. The Landolt C consists of a ring that has a gap, thus looking similar to the letter C. The gap can be at various positions (usually left, right, bottom, top and the 45° positions in between) and the task of the tested person is to decide on which side the gap is. The size of the C and its gap are reduced until the subject makes a specified rate of errors. The minimum perceivable angle of the gap is taken as measure of the visual acuity. It is generally practised in the laboratory. The stroke width is of the diameter, and the gap width is the same. This is identical to the letter C from a Snellen chart. The Landolt C is the standard optotype for acuity measurement in most European countries. It was standardized, together with measurement procedures, by the G ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
