{"id":114,"date":"2023-06-14T14:34:31","date_gmt":"2023-06-14T13:34:31","guid":{"rendered":"https:\/\/halleysclinic.com\/?p=114"},"modified":"2023-06-14T15:05:00","modified_gmt":"2023-06-14T14:05:00","slug":"how-do-we-see-colors","status":"publish","type":"post","link":"https:\/\/halleysclinic.com\/index.php\/2023\/06\/14\/how-do-we-see-colors\/","title":{"rendered":"HOW DO WE SEE COLORS?"},"content":{"rendered":"\n<ul class=\"wp-block-list\">\n<li><strong>BY DR. AK RANA<\/strong><\/li>\n<\/ul>\n\n\n\n<p>Ever played \u2018colors game\u2019 in childhood?<\/p>\n\n\n\n<p>Here, group of kids ask the one with the turn \u2018which color?\u2019 and he then name one color. Everyone have to run to touch that color, otherwise they are out of the game.<\/p>\n\n\n\n<p>Colors are wonders of life and they never fail to amaze us.<\/p>\n\n\n\n<h3 class=\"wp-block-heading has-pale-ocean-gradient-background has-background\"><strong><u>COLORS<\/u><\/strong><\/h3>\n\n\n\n<p>Light (visible spectrum of EM waves) travel in straight line.<\/p>\n\n\n\n<p>Light is made up of different wavelengths, each one having its own colour.<\/p>\n\n\n\n<p>For example,<\/p>\n\n\n\n<p>Red colour wavelength = 620- 780 nm<\/p>\n\n\n\n<p>Blue colour = 440 \u2013 490 nm<\/p>\n\n\n\n<p>Green color = 490 \u2013 570 nm<\/p>\n\n\n\n<p>When light strikes an object depending upon its property, object absorbs and reflect other wavelengths.<\/p>\n\n\n\n<p>For example, red dress will absorb all other wavelengths and reflect the red color, this reflected light falls on our eyes and we see it red!<\/p>\n\n\n\n<p>(You can say red dress doesn\u2019t like red colour and just reflected it back, while all others call it as \u2018red dress\u2019)<\/p>\n\n\n\n<p>White dress will reflect all wavelengths and black will absorb all.<\/p>\n\n\n\n<h2 class=\"wp-block-heading has-blush-light-purple-gradient-background has-background\"><strong>HOW DO WE SEE COLOURS<\/strong><\/h2>\n\n\n\n<p>Our eye has retina and in which photoreceptors are present.<\/p>\n\n\n\n<p>Photoreceptors are of two types \u2013<\/p>\n\n\n\n<p>Rods \u2013 associated with vision in dark<\/p>\n\n\n\n<p>Cones \u2013 associated with colours.<\/p>\n\n\n\n<p>In case of vitamin A deficiency, rods decrease and thereby decreased vision in night called as night blindness.<\/p>\n\n\n\n<p>Light travels through the<em> cornea, lens<\/em> and then reaches the <strong><em>retina.<\/em><\/strong><\/p>\n\n\n\n<p>Here cones interpret the colour combination and impulse is generated as passed through <em>optic nerve<\/em> to optic chiasma to <em>optic tract.<\/em><\/p>\n\n\n\n<p>Further ahead it travels to <em>lateral geniculate<\/em> and to <em>optic radiations<\/em> and finally in brain to <strong>visual cortex<\/strong>.<\/p>\n\n\n\n<p>Anywhere if there is lesion in the pathway, then defect in vision occurs.<\/p>\n\n\n\n<div class=\"wp-block-cover is-light\"><span aria-hidden=\"true\" class=\"wp-block-cover__background has-background-dim\"><\/span><img loading=\"lazy\" decoding=\"async\" width=\"940\" height=\"693\" class=\"wp-block-cover__image-background wp-image-115\" alt=\"beautiful colors of natur4e\" src=\"https:\/\/halleysclinic.com\/wp-content\/uploads\/2023\/06\/image-3.png\" data-object-fit=\"cover\" srcset=\"https:\/\/halleysclinic.com\/wp-content\/uploads\/2023\/06\/image-3.png 940w, https:\/\/halleysclinic.com\/wp-content\/uploads\/2023\/06\/image-3-300x221.png 300w, https:\/\/halleysclinic.com\/wp-content\/uploads\/2023\/06\/image-3-768x566.png 768w, https:\/\/halleysclinic.com\/wp-content\/uploads\/2023\/06\/image-3-600x442.png 600w\" sizes=\"auto, (max-width: 940px) 100vw, 940px\" \/><div class=\"wp-block-cover__inner-container is-layout-flow wp-block-cover-is-layout-flow\">\n<p><\/p>\n\n\n\n<p><\/p>\n\n\n\n<p><\/p>\n\n\n\n<p><\/p>\n\n\n\n<p><\/p>\n\n\n\n<p class=\"has-text-align-center has-large-font-size\">                                            <\/p>\n\n\n\n<p>halleysclinic.com<\/p>\n\n\n\n<p><\/p>\n\n\n\n<p class=\"has-text-align-center has-large-font-size\"><\/p>\n<\/div><\/div>\n\n\n\n<h2 class=\"wp-block-heading has-very-light-gray-to-cyan-bluish-gray-gradient-background has-background\"><strong><u>COLOUR BLINDNESS<\/u><\/strong><\/h2>\n\n\n\n<p>Colour is seen by combination of cones.<\/p>\n\n\n\n<p>The three primary colors are named as \u2013<\/p>\n\n\n\n<ol class=\"wp-block-list\" type=\"1\">\n<li>Red \u2013&nbsp;&nbsp;&nbsp; Prota<\/li>\n\n\n\n<li>Green \u2013 Deutra<\/li>\n\n\n\n<li>Blue&nbsp;&nbsp;&nbsp; &#8211;&nbsp; Trita<\/li>\n<\/ol>\n\n\n\n<p>Colour blindness can be acquired or congenital.<\/p>\n\n\n\n<p><strong>Congenital<\/strong> \u2013 X-linked recessive inheritance, seen most commonly in males.<\/p>\n\n\n\n<p>(Red and green colour blindness is most common)<\/p>\n\n\n\n<p><strong>Acquired<\/strong> in diseases like \u2013 cataract, macular diseases, optic nerve diseases etc.<\/p>\n\n\n\n<p><strong><u>Dichromatic<\/u><\/strong><\/p>\n\n\n\n<p>Perception of 1 colour is absent, so patient is able to see only 2 colours.<\/p>\n\n\n\n<ol class=\"wp-block-list\" type=\"1\">\n<li>Protanopia \u2013 Red colour blind<\/li>\n\n\n\n<li>Deuteranopia \u2013 Green colour blind<\/li>\n\n\n\n<li>Tritanopia&nbsp; &#8211; Blue colour blind<\/li>\n<\/ol>\n\n\n\n<p>Trichromatic anomaly<\/p>\n\n\n\n<p>can see all three colours but there is defect in one colour.<\/p>\n\n\n\n<ol class=\"wp-block-list\" type=\"1\">\n<li>Protanomaly \u2013 Red colour defect<\/li>\n\n\n\n<li>Deuteranomaly \u2013 Green colour defect<\/li>\n\n\n\n<li>Tritanomaly \u2013 Blue colour defect<\/li>\n<\/ol>\n\n\n\n<p class=\"has-cool-to-warm-spectrum-gradient-background has-background\"><strong>TESTS FOR COLOUR BLINDNESS<\/strong><\/p>\n\n\n\n<ol class=\"wp-block-list\" type=\"1\">\n<li>Ishihara chart \u2013 most common test<\/li>\n\n\n\n<li>Hardy Rand Rittler test \u2013 for children<\/li>\n\n\n\n<li>Farnsworth Munsell 100 hue<\/li>\n\n\n\n<li>Farnsworth Munsell 15 hue<\/li>\n<\/ol>\n\n\n\n<p>Can you hear your friend talking to you in space?<\/p>\n\n\n\n<p>No way! Because there is no atmosphere and sound waves need vibration of particles for its traveling and reaching our ears.<\/p>\n\n\n\n<p>Can you see your friend in space?<\/p>\n\n\n\n<p>Sure, because light waves do not need medium for traveling.<\/p>\n\n\n\n<p>You can use torch on moon but not radio!<\/p>\n\n\n\n<p>Still, we need source of light.<\/p>\n\n\n\n<p>If you are close to sun or any other star, you will reflect its light and see each other.<\/p>\n\n\n\n<p>But, if there is no source, you won\u2019t be able to see.<\/p>\n\n\n\n<p>We can see moon because of sun, moon reflects sun\u2019s light. The thing is light need to reach our eyes, for us to interpret it.<\/p>\n\n\n\n<p>There are so many shades of single colour, some distinguish them apart, others not so much.<\/p>\n\n\n\n<p>Nevertheless, these colors make our world beautiful and lively.<\/p>\n\n\n\n<p class=\"has-pale-ocean-gradient-background has-background\">SHARE YOUR VIEWS AND STORIES IN COMMENT SECTION OR <\/p>\n\n\n\n<p class=\"has-pale-ocean-gradient-background has-background\">CONTACT HALLEYS CLINIC TEAM &#8211; halleysclinic@gmail.com<\/p>\n\n\n\n<p>also read <a href=\"https:\/\/halleysclinic.com\/index.php\/2023\/05\/31\/why-do-we-feel-hungry\/\" title=\"WHY DO WE FEEL HUNGRY?\">WHY DO WE FEEL HUNGRY?<\/a><\/p>\n\n\n\n<p>also read <a href=\"https:\/\/halleysclinic.com\/index.php\/2023\/05\/19\/how-memory-is-stored-in-brain\/\" title=\"HOW MEMORY IS STORED IN BRAIN?\">HOW MEMORY IS STORED IN BRAIN?<\/a><\/p>\n\n\n\n<p><\/p>\n\n\n\n<p><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Ever played \u2018colors game\u2019 in childhood? Here, group of kids ask the one with the&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"om_disable_all_campaigns":false,"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"categories":[36],"tags":[95,101,24,96,82,100,97,98,99],"class_list":["post-114","post","type-post","status-publish","format-standard","hentry","category-wonders-of-life","tag-colors","tag-health","tag-healthy-lifestyle","tag-how-do-we-see-colors","tag-medical-science","tag-tests-for-color-blindness","tag-what-are-cons","tag-what-are-rods","tag-what-is-color-blindness"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/halleysclinic.com\/index.php\/wp-json\/wp\/v2\/posts\/114","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/halleysclinic.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/halleysclinic.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/halleysclinic.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/halleysclinic.com\/index.php\/wp-json\/wp\/v2\/comments?post=114"}],"version-history":[{"count":3,"href":"https:\/\/halleysclinic.com\/index.php\/wp-json\/wp\/v2\/posts\/114\/revisions"}],"predecessor-version":[{"id":118,"href":"https:\/\/halleysclinic.com\/index.php\/wp-json\/wp\/v2\/posts\/114\/revisions\/118"}],"wp:attachment":[{"href":"https:\/\/halleysclinic.com\/index.php\/wp-json\/wp\/v2\/media?parent=114"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/halleysclinic.com\/index.php\/wp-json\/wp\/v2\/categories?post=114"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/halleysclinic.com\/index.php\/wp-json\/wp\/v2\/tags?post=114"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}