{"id":1573,"date":"2010-05-30T05:00:40","date_gmt":"2010-05-30T05:00:40","guid":{"rendered":"http:\/\/xromata.com\/?p=1573"},"modified":"2014-03-15T08:26:12","modified_gmt":"2014-03-15T08:26:12","slug":"1573","status":"publish","type":"post","link":"https:\/\/xromata.com\/?p=1573","title":{"rendered":"\u03a1\u03b1\u03b2\u03b4\u03af\u03b1 – \u039a\u03c9\u03bd\u03af\u03b1 Rods – Cones"},"content":{"rendered":"

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\u038cπως ε\u03afδαμε <\/font>http:\/\/xromata.com\/?p=1373<\/font><\/a> η λειτουργ\u03afα της \u03ccρασης βασ\u03afζεται στα ραβδ\u03afα και στα κων\u03afα, \u03ccπου τα μεν πρ\u03ceτα αντιλαμβ\u03acνονται την αμυδρ\u03ccτερη επ\u03adλαση του φωτ\u03ccς, τα δε δε\u03cdτερα ερεθ\u03afζονται με περισσ\u03ccτερη ποσ\u03ccτητα φωτ\u03ccς, το οπο\u03afο και διαχωρ\u03afζουν σε χρωματικ\u03adς ακτινοβολ\u03afες.<\/o:p><\/font><\/font><\/span><\/p>\n

Ας δο\u03cdμε τις διαφορ\u03adς μεταξ\u03cd αυτ\u03ceν των δυο φωτοσυλλεκτ\u03ceν.<\/font><\/font><\/span><\/p>\n

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Διαφορ\u03adς μεταξ\u03cd ραβδ\u03afων και κων\u03afων<\/o:p><\/font><\/font><\/span><\/u><\/b><\/p>\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
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Ραβδ\u03afα<\/o:p><\/font><\/font><\/span><\/b><\/p>\n<\/td>\n

\n

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Κων\u03afα<\/o:p><\/font><\/font><\/span><\/b><\/p>\n<\/td>\n<\/tr>\n

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Χρησιμε\u03cdουν για την σκοτοπικ\u03ae \u03ccραση.<\/o:p><\/font><\/font><\/span><\/p>\n

Σκοτοπικ\u03ae καλε\u03afται η \u03ccραση που εκτελε\u03afται απ\u03cc τον οφθαλμ\u03cc κ\u03acτω απ\u03cc συνθ\u03aeκες χαμηλο\u03cd φωτισμο\u03cd. <\/o:p><\/font><\/font><\/span><\/p>\n

Ετυμολογικ\u03ac ο \u03ccρος σκοτοπικ\u03ae \u03ccραση κατ\u03acγεται απ\u03cc τις Ελληνικ\u03adς λ\u03adξεις σκ\u03ccτος και –οπ\u03afα (σημα\u03afνουσα την κατ\u03acσταση \u03ccρασης). <\/span><\/o:p><\/span><\/font><\/font><\/p>\n<\/td>\n

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Χρησιμε\u03cdουν για την φωτοπικ\u03ae \u03ccραση.<\/o:p><\/font><\/font><\/span><\/p>\n

Φωτοπικ\u03ae καλε\u03afται η \u03ccραση που εκτελε\u03afται απ\u03cc τον οφθαλμ\u03cc κ\u03acτω απ\u03cc συνθ\u03aeκες καλο\u03cd φωτισμο\u03cd<\/o:p><\/font><\/font><\/span><\/p>\n

Στον \u03acνθρωπο και σε πολλ\u03ac \u03acλλα ζ\u03ceα δια της φωτοπικ\u03aeς \u03ccρασης επιτυγχ\u03acνεται η χρωματικ\u03ae αντ\u03afληψη με την μεσολ\u03acβηση των κων\u03afων. <\/o:p><\/font><\/font><\/span><\/p>\n<\/td>\n<\/tr>\n

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Πολ\u03cd φωτοευα\u03afσθητα. Ευαισθητοποιο\u03cdνται με το διασκορπισμ\u03adνο τριγ\u03cdρω τους φως.<\/o:p><\/font><\/font><\/span><\/p>\n<\/td>\n

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\u038cχι τ\u03ccσο φωτοευα\u03afσθητα. Ευαισθητοποιο\u03cdνται μ\u03ccνο απ\u03cc το φως που π\u03adφτει κατευθε\u03afαν επ\u03acνω τους.<\/o:p><\/font><\/font><\/span><\/p>\n<\/td>\n<\/tr>\n

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Η \u03adλλειψ\u03ae τους επιφ\u03adρει νυκταλωπ\u03afα, μια κατ\u03acσταση που κ\u03acνει δ\u03cdσκολη η αδ\u03cdνατη την \u03ccραση σε επ\u03afπεδα χαμηλο\u03cd φωτισμο\u03cd.<\/o:p><\/font><\/font><\/span><\/p>\n

Η νυκταλωπ\u03afα μπορε\u03af να υπ\u03acρχει εκ γενετ\u03aeς \u03ae να προκληθε\u03af απ\u03cc τραυματισμ\u03cc \u03ae κακ\u03ae διατροφ\u03ae, πχ. \u03adλλειψη βιταμ\u03afνης Α.<\/o:p><\/font><\/font><\/span><\/p>\n<\/td>\n

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Η \u03adλλειψη κων\u03afων επιφ\u03adρει νομικ\u03ae τ\u03cdφλωση.<\/o:p><\/font><\/font><\/span><\/p>\n

Αυτ\u03cc σημα\u03afνει \u03ccτι \u03adνα \u03acτομο θεωρε\u03afται νομικ\u03ac τυφλ\u03cc \u03ccταν διακρ\u03afνει \u03adνα αντικε\u03afμενο  <\/span>σε απ\u03ccσταση 6 μ\u03adτρων –με διορθωτικο\u03cdς φακο\u03cdς- με τον \u03afδιο βαθμ\u03cc ευκρ\u03afνειας που \u03adνα \u03acτομο βλ\u03adπει το αντικε\u03afμενο αυτ\u03cc, σε απ\u03ccσταση 60 μ\u03adτρων.<\/o:p><\/font><\/font><\/span><\/p>\n<\/td>\n<\/tr>\n

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Χαμηλ\u03ae οπτικ\u03ae οξ\u03cdτητα.<\/o:p><\/font><\/font><\/span><\/p>\n<\/td>\n

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Υψηλ\u03ae οπτικ\u03ae οξ\u03cdτητα. Καλ\u03cdτερη χωροταξικ\u03ae αν\u03acλυση.<\/o:p><\/font><\/font><\/span><\/p>\n<\/td>\n<\/tr>\n

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Δεν ευρ\u03afσκονται στο βοθρ\u03afο.<\/o:p><\/font><\/font><\/span><\/p>\n<\/td>\n

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Επικεντρ\u03ceνονται στο βοθρ\u03afο.<\/o:p><\/font><\/font><\/span><\/p>\n<\/td>\n<\/tr>\n

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Αργ\u03ae ανταπ\u03ccκριση στο φως, οι σκοτοπτικο\u03af διαχωρισμο\u03af επ\u03adρχονται με την π\u03acροδο κ\u03acποιου χρ\u03ccνου.<\/o:p><\/font><\/font><\/span><\/p>\n<\/td>\n

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\u0386μεση ανταπ\u03ccκριση στο φως, αντιλαμβ\u03acνονται ταχ\u03cdτατα τις φωτοπτικ\u03adς αλλαγ\u03adς.<\/o:p><\/font><\/font><\/span><\/p>\n<\/td>\n<\/tr>\n

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Περι\u03adχουν μεγαλ\u03cdτερη ποσ\u03ccτητα φωτοχρωστικ\u03aeς \u03ceστε να ανιχνε\u03cdουν χαμηλ\u03ccτερα επ\u03afπεδα φωτισμο\u03cd.<\/o:p><\/font><\/font><\/span><\/p>\n<\/td>\n

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Περι\u03adχουν μικρ\u03ccτερη ποσ\u03ccτητα φωτοχρωστικ\u03aeς απ\u03cc τα ραβδ\u03afα και χρει\u03acζονται περισσ\u03ccτερο φως για να διακρ\u03afνουν ευκριν\u03adστερα τις εικ\u03ccνες.<\/o:p><\/font><\/font><\/span><\/p>\n<\/td>\n<\/tr>\n

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Υπ\u03acρχουν 20 φορ\u03adς περισσ\u03ccτερα ραβδ\u03afα απ\u03cc κων\u03afα στον αμφιβληστροειδ\u03ae.<\/o:p><\/font><\/font><\/span><\/p>\n<\/td>\n

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 <\/span>Περι\u03adχουν \u03adνα τ\u03cdπο φωτοευα\u03afσθητης χρωστικ\u03aeς ουσ\u03afας.<\/o:p><\/font><\/font><\/span><\/p>\n<\/td>\n

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Περι\u03adχουν 3 τ\u03cdπους φωτοευα\u03afσθητης χρωστικ\u03aeς ουσ\u03afας, στον ανθρ\u03ceπινο οφθαλμ\u03cc.<\/o:p><\/font><\/font><\/span><\/p>\n<\/td>\n<\/tr>\n

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Παρ\u03adχουν<\/span> <\/span>αχρωματικ\u03ae<\/span> <\/span>\u03ccραση<\/span>.<\/o:p><\/span><\/font><\/font><\/p>\n<\/td>\n

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Παρ\u03adχουν χρωματικ\u03ae \u03ccραση.<\/o:p><\/font><\/font><\/span><\/p>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

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Translated into English<\/o:p><\/font><\/span><\/u><\/span><\/p>\n

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Difference between rods and cones<\/o:p><\/font><\/font><\/font><\/span><\/u><\/span><\/h3>\n

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As seen in http:\/\/xromata.com\/?p=1373 function of vision is based on rods and cones, where the first ones sense the dimmest advent of light and the second ones are stimulated by much more amount of light, which is separated by them into chromatic radiation.<\/font><\/span><\/span>
\nLet’s see the differences between these two photoreceptors.<\/span><\/o:p><\/font><\/font><\/span><\/p>\n

Comparison of rod and cone cells.<\/o:p><\/font><\/font><\/span><\/u><\/p>\n

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\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
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Rods <\/o:p><\/font><\/font><\/b><\/p>\n<\/td>\n

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Cones<\/o:p><\/font><\/font><\/b><\/p>\n<\/td>\n<\/tr>\n

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Used<\/span> <\/span>for<\/span> <\/span><\/font><\/font>scotopic<\/span> <\/span>vision<\/span><\/font><\/font><\/font><\/a><\/p>\n

Scotopic vision<\/span><\/b> is the vision of the <\/span><\/font><\/font>eye<\/font><\/span><\/a> under low light conditions. <\/o:p><\/span><\/font><\/font><\/span><\/p>\n

The term comes from <\/font><\/span>Greek<\/font><\/span><\/a> skotos<\/span><\/i> meaning darkness<\/i> and -opia<\/i> meaning a condition of sight<\/o:p><\/i><\/span><\/font><\/font><\/span><\/p>\n<\/td>\n

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Used<\/span> <\/span>for<\/span> <\/span><\/font><\/font>photopic<\/span> <\/span>vision<\/span><\/font><\/font><\/font><\/a><\/p>\n

Photopic vision<\/span><\/b> is the <\/span><\/font><\/font>vision<\/font><\/span><\/a> of the <\/font><\/span>eye<\/font><\/span><\/a> under well-lit conditions. <\/o:p><\/font><\/font><\/span><\/p>\n

In humans and many animals, photopic vision allows <\/font><\/span>color perception<\/font><\/span><\/a>, mediated by <\/font><\/span>cone cells<\/font><\/span><\/a>.<\/o:p><\/font><\/font><\/span><\/p>\n<\/td>\n<\/tr>\n

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 <\/span>Very light <\/span><\/font><\/font><\/span>sensitive<\/font><\/span><\/a>; sensitive to scattered light<\/o:p><\/font><\/font><\/span><\/p>\n<\/td>\n

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Not very light sensitive; sensitive to only direct light<\/o:p><\/font><\/font><\/span><\/p>\n<\/td>\n<\/tr>\n

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Loss causes <\/font><\/span>night blindness<\/font><\/span><\/a><\/o:p><\/span><\/p>\n

is a condition making it difficult or impossible to see in relatively low light. It is a symptom of several eye diseases. Night blindness may exist from birth, or be caused by injury or malnutrition (for example, a lack of <\/font><\/span>vitamin A<\/font><\/span><\/a>). <\/o:p><\/span><\/font><\/font><\/span><\/p>\n<\/td>\n

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Loss causes <\/font><\/span>legal blindness<\/font><\/span><\/a><\/o:p><\/span><\/p>\n

This means that a legally blind individual would have to stand 20 feet (6.1 m) from an object to see it—with <\/font><\/span>corrective lenses<\/font><\/span><\/a>—with the same degree of clarity as a normally sighted person could from 200 feet (61 m).<\/o:p><\/font><\/font><\/span><\/p>\n<\/td>\n<\/tr>\n

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Low visual acuity<\/font><\/p>\n<\/td>\n

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High visual acuity; better spatial resolution<\/o:p><\/font><\/font><\/span><\/p>\n<\/td>\n<\/tr>\n

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Not<\/span> <\/span>present<\/span> <\/span>in<\/span> <\/span><\/font><\/font>fovea<\/font><\/span><\/a><\/p>\n<\/td>\n

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Concentrated in <\/font><\/span>fovea<\/font><\/a><\/p>\n<\/td>\n<\/tr>\n

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Slow response to light, stimuli added over time<\/o:p><\/font><\/font><\/span><\/p>\n<\/td>\n

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Fast response to light, can perceive more rapid changes in stimuli<\/o:p><\/font><\/font><\/span><\/p>\n<\/td>\n<\/tr>\n

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Have more pigment than cones, so can detect lower light levels<\/o:p><\/font><\/font><\/span><\/p>\n<\/td>\n

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Have less pigment than rods, require more light to detect images<\/o:p><\/font><\/font><\/span><\/p>\n<\/td>\n<\/tr>\n

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Stacks of membrane-enclosed disks are unattached to cell membrane directly<\/o:p><\/font><\/font><\/span><\/p>\n<\/td>\n

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Disks are attached to outer membrane<\/o:p><\/font><\/font><\/span><\/p>\n<\/td>\n<\/tr>\n

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20 times more rods than cones in the retina<\/o:p><\/font><\/font><\/span><\/p>\n<\/td>\n

 <\/td>\n<\/tr>\n
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One<\/span> <\/span>type<\/span> <\/span>of<\/span> <\/span><\/font><\/font>photosensitive<\/font><\/span><\/a> pigment<\/span><\/font><\/font><\/p>\n<\/td>\n

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Three types of <\/font><\/span>photosensitive<\/font><\/span><\/a> pigment in humans<\/o:p><\/font><\/font><\/span><\/p>\n<\/td>\n<\/tr>\n

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Confer achromatic vision<\/o:p><\/font><\/font><\/span><\/p>\n<\/td>\n

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Confer color vision<\/font><\/p>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

 <\/p>\n

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 <\/p>\n","protected":false},"excerpt":{"rendered":"

    \u038cπως ε\u03afδαμε http:\/\/xromata.com\/?p=1373 η λειτουργ\u03afα της \u03ccρασης βασ\u03afζεται στα ραβδ\u03afα και στα κων\u03afα, \u03ccπου τα μεν πρ\u03ceτα αντιλαμβ\u03acνονται την αμυδρ\u03ccτερη επ\u03adλαση του φωτ\u03ccς, τα δε δε\u03cdτερα ερεθ\u03afζονται με περισσ\u03ccτερη ποσ\u03ccτητα φωτ\u03ccς, το οπο\u03afο και διαχωρ\u03afζουν σε χρωματικ\u03adς ακτινοβολ\u03afες. Ας δο\u03cdμε τις διαφορ\u03adς μεταξ\u03cd αυτ\u03ceν των δυο φωτοσυλλεκτ\u03ceν.       Διαφορ\u03adς μεταξ\u03cd ραβδ\u03afων […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[20],"tags":[35,304,383,309,381,39,36,379,313,303,377,380,461,376,378,382],"class_list":["post-1573","post","type-post","status-publish","format-standard","hentry","category-leitourgies-orasis-xromatwn","tag-aktinovolia","tag-304","tag-383","tag-309","tag-381","tag-konia","tag-mati","tag-379","tag-313","tag-303","tag-377","tag-380","tag-fos","tag-376","tag-378","tag-382"],"_links":{"self":[{"href":"https:\/\/xromata.com\/index.php?rest_route=\/wp\/v2\/posts\/1573","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/xromata.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/xromata.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/xromata.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/xromata.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1573"}],"version-history":[{"count":12,"href":"https:\/\/xromata.com\/index.php?rest_route=\/wp\/v2\/posts\/1573\/revisions"}],"predecessor-version":[{"id":6134,"href":"https:\/\/xromata.com\/index.php?rest_route=\/wp\/v2\/posts\/1573\/revisions\/6134"}],"wp:attachment":[{"href":"https:\/\/xromata.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1573"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/xromata.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1573"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/xromata.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1573"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}