{"id":2282,"date":"2019-08-07T12:50:23","date_gmt":"2019-08-07T17:50:23","guid":{"rendered":"http:\/\/scienceandsf.com\/?p=2282"},"modified":"2019-08-07T12:50:25","modified_gmt":"2019-08-07T17:50:25","slug":"controversy-erupts-over-claims-that-newly-invented-glasses-can-correct-colourblindness","status":"publish","type":"post","link":"https:\/\/scienceandsf.com\/index.php\/2019\/08\/07\/controversy-erupts-over-claims-that-newly-invented-glasses-can-correct-colourblindness\/","title":{"rendered":"Controversy erupts over claims that newly invented glasses can correct colourblindness."},"content":{"rendered":"\n<p>Before I start to discuss colourblindness perhaps I should start by taking a moment to talk briefly about how it is that we are able to see colour in the first place. Now most people are familiar with the fact that at the back of our eyes, the retina, there are two groups of light sensitive cells that are called rods and cones based upon their shape. The rods are sensitive to the intensity of the light whatever the colour, if we had only rods we’d see everything in black and white, complete colourblindness. <\/p>\n\n\n\n<figure class=\"wp-block-image\"><img loading=\"lazy\" decoding=\"async\" width=\"840\" height=\"480\" src=\"http:\/\/scienceandsf.com\/wp-content\/uploads\/2019\/08\/1_EN.jpg\" alt=\"\" class=\"wp-image-2284\" srcset=\"https:\/\/scienceandsf.com\/wp-content\/uploads\/2019\/08\/1_EN.jpg 840w, https:\/\/scienceandsf.com\/wp-content\/uploads\/2019\/08\/1_EN-300x171.jpg 300w, https:\/\/scienceandsf.com\/wp-content\/uploads\/2019\/08\/1_EN-768x439.jpg 768w\" sizes=\"auto, (max-width: 709px) 85vw, (max-width: 909px) 67vw, (max-width: 1362px) 62vw, 840px\" \/><figcaption>The Anatomy of the Human Eye (Credit: Wikipedia)<\/figcaption><\/figure>\n\n\n\n<p>The\ncones on the other hand come in three types; some are sensitive to the longer\nwavelengths of visible light, the colour red. Others are sensitive to the\nshorter visible wavelengths, the colour blue. The final group is sensitive to\nthe middle wavelengths, the colour green. Together these three types of cones\ngive us the ability to distinguish thousands of shades of colour.<\/p>\n\n\n\n<p>Colourblindness\nis defined as a decreased ability to discern the full range of the colour\nspectrum of visible light. In other words some of the cone cells are not\nfunctioning properly. <\/p>\n\n\n\n<p>The most common form of colourblindness consists of some degree of difficulty in distinguishing between the colours red and green and is known clinically as dichromatic. Dichromatic colourblindness is both genetic in nature and sex related since the gene for the red \/ green cone cells occurs on the X chromosome of the X-y sex pair.<\/p>\n\n\n\n<figure class=\"wp-block-image\"><img loading=\"lazy\" decoding=\"async\" width=\"500\" height=\"225\" src=\"http:\/\/scienceandsf.com\/wp-content\/uploads\/2019\/08\/1-SchoolWorkHelper.jpg\" alt=\"\" class=\"wp-image-2285\" srcset=\"https:\/\/scienceandsf.com\/wp-content\/uploads\/2019\/08\/1-SchoolWorkHelper.jpg 500w, https:\/\/scienceandsf.com\/wp-content\/uploads\/2019\/08\/1-SchoolWorkHelper-300x135.jpg 300w\" sizes=\"auto, (max-width: 500px) 85vw, 500px\" \/><figcaption>How people with Dichromatic colourblindness see the world (Credit: School Work Helper)<\/figcaption><\/figure>\n\n\n\n<p>The defective gene for colourblindness is recessive in nature so since women have two X sex chromosomes both of the chromosomes must have the defective gene in order for her to be colourblind. A woman with only a single defective X chromosome can be a ‘carrier’ of colourblindness however.<\/p>\n\n\n\n<figure class=\"wp-block-image\"><img loading=\"lazy\" decoding=\"async\" width=\"1417\" height=\"987\" src=\"http:\/\/scienceandsf.com\/wp-content\/uploads\/2019\/08\/SexChromo-Socratic.jpg\" alt=\"\" class=\"wp-image-2286\" srcset=\"https:\/\/scienceandsf.com\/wp-content\/uploads\/2019\/08\/SexChromo-Socratic.jpg 1417w, https:\/\/scienceandsf.com\/wp-content\/uploads\/2019\/08\/SexChromo-Socratic-300x209.jpg 300w, https:\/\/scienceandsf.com\/wp-content\/uploads\/2019\/08\/SexChromo-Socratic-768x535.jpg 768w, https:\/\/scienceandsf.com\/wp-content\/uploads\/2019\/08\/SexChromo-Socratic-1200x836.jpg 1200w\" sizes=\"auto, (max-width: 709px) 85vw, (max-width: 909px) 67vw, (max-width: 1362px) 62vw, 840px\" \/><figcaption>The X-Y Chromosomes determine whether you’s a girl or a boy but can also carry sex related mutations like colourblindness and hair loss (Credit: Socratic)<\/figcaption><\/figure>\n\n\n\n<p>A\nmale on the other hand has only one X sex chromosome, which he gets from his\nmother. Therefore if a woman is colourblind all of her male offspring will be\ncolourblind. If a woman is only a carrier of colourblindness then half of her\nsons will inherit the defective gene and develop colourblindness. Because of\nthis many more men are colourblind, about 8%, as opposed to women, 0.5%.<\/p>\n\n\n\n<p>Colourblindness varies in degree with most colourblind people having only a small loss of colour vision. The chart below shows the different recognized ‘types’ of colourblindness along with the percentage of the population effected.<\/p>\n\n\n\n<figure class=\"wp-block-image\"><img loading=\"lazy\" decoding=\"async\" width=\"495\" height=\"238\" src=\"http:\/\/scienceandsf.com\/wp-content\/uploads\/2019\/08\/Colourblindness-wiki.jpg\" alt=\"\" class=\"wp-image-2287\" srcset=\"https:\/\/scienceandsf.com\/wp-content\/uploads\/2019\/08\/Colourblindness-wiki.jpg 495w, https:\/\/scienceandsf.com\/wp-content\/uploads\/2019\/08\/Colourblindness-wiki-300x144.jpg 300w\" sizes=\"auto, (max-width: 495px) 85vw, 495px\" \/><figcaption>Types of Colourblindnesss and percent of population effected (Credit: Wikipedia)<\/figcaption><\/figure>\n\n\n\n<p>Determining whether of not a person has colourblindness is usually accomplished by testing them with one or more Ishihara colour test plates, an example of which is given below. In this example a person with normal colour vision can clearly see the number 27 in the center of the design while a person with a slight colour deficiency will see the number 21. A person with total red \/ green colourblindness will not see any number at all!<\/p>\n\n\n\n<figure class=\"wp-block-image\"><img loading=\"lazy\" decoding=\"async\" width=\"1395\" height=\"1375\" src=\"http:\/\/scienceandsf.com\/wp-content\/uploads\/2019\/08\/27.jpg\" alt=\"\" class=\"wp-image-2289\" srcset=\"https:\/\/scienceandsf.com\/wp-content\/uploads\/2019\/08\/27.jpg 1395w, https:\/\/scienceandsf.com\/wp-content\/uploads\/2019\/08\/27-300x296.jpg 300w, https:\/\/scienceandsf.com\/wp-content\/uploads\/2019\/08\/27-768x757.jpg 768w, https:\/\/scienceandsf.com\/wp-content\/uploads\/2019\/08\/27-1200x1183.jpg 1200w\" sizes=\"auto, (max-width: 709px) 85vw, (max-width: 909px) 67vw, (max-width: 1362px) 62vw, 840px\" \/><figcaption>An Ishihara test for Red-Green Colourblindness (Credit: Wikipedia)<\/figcaption><\/figure>\n\n\n\n<p>There is no cure for colourblindness. Recently however there have been attempts to ‘correct’ colourblindness with specially designed glasses in a manner similar to the way that near or farsightedness can be corrected. The glasses are commercially available under the trademarked name EnChroma\u00ae and were developed by developed by a pair of scientists, Andrew Schmeder, a mathematician who studies the psychology of perception, and Don McPherson a glass researcher who has invented specialized laser safety glasses for surgeons.<\/p>\n\n\n\n<figure class=\"wp-block-image\"><img loading=\"lazy\" decoding=\"async\" width=\"677\" height=\"355\" src=\"http:\/\/scienceandsf.com\/wp-content\/uploads\/2019\/08\/enchroma-glasses-1200x630-allaboutvision.jpg\" alt=\"\" class=\"wp-image-2288\" srcset=\"https:\/\/scienceandsf.com\/wp-content\/uploads\/2019\/08\/enchroma-glasses-1200x630-allaboutvision.jpg 677w, https:\/\/scienceandsf.com\/wp-content\/uploads\/2019\/08\/enchroma-glasses-1200x630-allaboutvision-300x157.jpg 300w\" sizes=\"auto, (max-width: 709px) 85vw, (max-width: 909px) 67vw, (max-width: 984px) 61vw, (max-width: 1362px) 45vw, 600px\" \/><figcaption>How the Enchroma glasses are supposed to work (Credit: All About Vision)<\/figcaption><\/figure>\n\n\n\n<p>According\nto the inventors the EnChroma\u00ae glasses work by eliminating just those\nwavelengths of red and green light that confuse the eye’s cone cell receptor\nwhich allows the brain to perceive a greater colour contrast. EnChroma\u00ae Inc.\nestimates that 80% of colourblind people can see improved colour vision with\nthe help of the glasses and judging by the reaction in Youtube videos of\ncolourblind people who try them for the first time they succeed miraculously. <\/p>\n\n\n\n<p>Not\neverybody is so convinced however. Researchers at the University of Grenada’s\ndepartment of Optics in Spain have conducted a test of the EnChroma\u00ae glasses\nwith 48 colourblind individuals, over 200 people volunteered for the test. The\nresults of this study, which were published in the journal Optics Express, seem\nto show that the EnChroma\u00ae glasses only marginally perform better than ordinary\nhunting glasses at increasing colour perception. The conclusion reached was\nthat the wearers of EnChroma\u00ae do not perceive new colours so much as see the\nsame colours in a new way.<\/p>\n\n\n\n<p>Sounds\na bit like we’re arguing semantics to me. While it’s true that the claims made\nby EnChroma\u00ae Inc are exaggerated, they’re trying to sell the glasses after all,\nthe company has never claimed to be able to ‘cure’ colourblindness. Reality is\nprobably somewhere in the middle with the EnChroma\u00ae glasses allowing people\nwith a mild form of red \/ green colourblindness to separate the two colours\nmore readily.<\/p>\n\n\n\n<p>And\nat least that’s a start. The development of EnChroma\u00ae glasses is the first even\nslightly successful treatment for colourblindness. Hopefully in the years to\ncome improved versions of the glasses will be developed that perform better,\nand for more types of colourblindness. <\/p>\n\n\n\n<p>In\nthe long run there has been some research conducted by Maureen Neitz at the\nUniversity of Washington that has employed gene therapy to cure colourblindness\nin monkeys. It may in fact be only a few years before there are some treatments\navailable that can significantly improve the ability of people born with\ncolourblindness to see the world with all of the rich tapestry of colours the\nrest of us take for granted everyday.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Before I start to discuss colourblindness perhaps I should start by taking a moment to talk briefly about how it is that we are able to see colour in the first place. Now most people are familiar with the fact that at the back of our eyes, the retina, there are two groups of light … <a href=\"https:\/\/scienceandsf.com\/index.php\/2019\/08\/07\/controversy-erupts-over-claims-that-newly-invented-glasses-can-correct-colourblindness\/\" class=\"more-link\">Continue reading<span class=\"screen-reader-text\"> “Controversy erupts over claims that newly invented glasses can correct colourblindness.”<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[12],"tags":[802,803,804,805],"class_list":["post-2282","post","type-post","status-publish","format-standard","hentry","category-science","tag-colourblindness","tag-enchroma-glasses","tag-sex-related-genetic-disorders","tag-vision-and-the-eye"],"_links":{"self":[{"href":"https:\/\/scienceandsf.com\/index.php\/wp-json\/wp\/v2\/posts\/2282","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/scienceandsf.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/scienceandsf.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/scienceandsf.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/scienceandsf.com\/index.php\/wp-json\/wp\/v2\/comments?post=2282"}],"version-history":[{"count":2,"href":"https:\/\/scienceandsf.com\/index.php\/wp-json\/wp\/v2\/posts\/2282\/revisions"}],"predecessor-version":[{"id":2290,"href":"https:\/\/scienceandsf.com\/index.php\/wp-json\/wp\/v2\/posts\/2282\/revisions\/2290"}],"wp:attachment":[{"href":"https:\/\/scienceandsf.com\/index.php\/wp-json\/wp\/v2\/media?parent=2282"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/scienceandsf.com\/index.php\/wp-json\/wp\/v2\/categories?post=2282"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/scienceandsf.com\/index.php\/wp-json\/wp\/v2\/tags?post=2282"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}