{"id":12637,"date":"2021-06-09T06:35:06","date_gmt":"2021-06-09T06:35:06","guid":{"rendered":"https:\/\/www.optometrists.org\/?page_id=12637"},"modified":"2021-07-15T09:16:53","modified_gmt":"2021-07-15T09:16:53","slug":"why-do-optometrists-use-eye-charts","status":"publish","type":"page","link":"https:\/\/www.optometrists.org\/general-practice-optometry\/guide-to-eye-exams\/eye-exams\/why-do-optometrists-use-eye-charts\/","title":{"rendered":"Why Do Optometrists Use Eye Charts?\u00a0"},"content":{"rendered":"<h2><b>Did you know that the Snellen eye chart is the most commonly used chart during an eye exam?<\/b><\/h2>\n<p>If you\u2019ve ever had an eye exam, you&#8217;re probably familiar with the eye chart of letters on the wall that your eye doctor asked you to read.<\/p>\n<h2><b>What is 20\/20 vision?<\/b><\/h2>\n<p>Before understanding the eye chart, it is important to know what 20\/20 vision actually means.<\/p>\n<p>It&#8217;s a numerical representation of how well you can see something from a distance of 20 feet in comparison to someone with &#8220;perfect&#8221; vision looking at the same object from the same distance.<\/p>\n<p>Your visual acuity may be 20\/100 if you have poor eyesight or \u2018low vision\u2019.<\/p>\n<p>This means that someone with perfect vision standing 100 feet away can read the tiniest line on the eye chart that you can read at 20 feet.<\/p>\n<p><a href=\"https:\/\/www.optometrists.org\/practice-search\/\"><b>Schedule an eye exam<\/b><\/a> with an eye doctor near you to see if you have 20\/20 vision or need glasses or an updated prescription.<\/p>\n<p><strong>SEE RELATED: <\/strong><a href=\"https:\/\/www.optometrists.org\/general-practice-optometry\/guide-to-eye-exams\/eye-exams\/what-is-a-visual-acuity-test\/\">What Is a Visual Acuity Test?<\/a><\/p>\n\n\t<div class=\"practice-search-widget\">\n\t\t<h3>Find an eye doctor near you<\/h3>\n\t\t\n\t<form class=\"practice-search-form practice-search-form-widget\" action=\"https:\/\/www.optometrists.org\/practice-search\/results\/\" method=\"get\">\n\n\t\t<input type=\"hidden\" name=\"distance\" value=\"100\" class=\"practice-search-distance\">\n\t\t<input type=\"hidden\" name=\"page\" class=\"practice-search-page\">\n\t\t<input type=\"hidden\" name=\"address_latitude\"><input type=\"hidden\" name=\"address_longitude\">\n\n\t\t<input type=\"text\" name=\"address\" class=\"practice-search-address\" placeholder=\"City, Surburb or Address\" value=\"\">\n\n\t\t\n\t\t\t<input type=\"hidden\" name=\"distance\" value=\"100\" class=\"practice-search-distance\">\n\n\t\t\n\n\t\t<button type=\"submit\" class=\"practice-search-button\">\n\t\t\t\t\t\t\t\t\t<svg width=\"19\" height=\"19\" viewBox=\"0 0 19 19\" fill=\"none\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"><path fill-rule=\"evenodd\" clip-rule=\"evenodd\" d=\"M10.6796 0.130005C9.15708 0.130059 7.66615 0.5646 6.38198 1.38258C5.09781 2.20057 4.07373 3.36803 3.43004 4.74783C2.78634 6.12763 2.54976 7.66246 2.74808 9.17205C2.9464 10.6816 3.57139 12.1033 4.54964 13.27L0.729639 17.08C0.6364 17.1732 0.562439 17.2839 0.511979 17.4058C0.461519 17.5276 0.435547 17.6581 0.435547 17.79C0.435547 17.9219 0.461519 18.0524 0.511979 18.1743C0.562439 18.2961 0.6364 18.4068 0.729639 18.5C0.917942 18.6883 1.17334 18.7941 1.43964 18.7941C1.5715 18.7941 1.70207 18.7681 1.82389 18.7177C1.94571 18.6672 2.0564 18.5932 2.14964 18.5L5.99964 14.62C7.35406 15.6038 8.98566 16.1324 10.6596 16.13C12.7814 16.13 14.8162 15.2871 16.3165 13.7869C17.8168 12.2866 18.6596 10.2517 18.6596 8.13C18.6596 6.00827 17.8168 3.97344 16.3165 2.47315C14.8162 0.97286 12.7814 0.130005 10.6596 0.130005H10.6796ZM10.6796 14.13C9.49295 14.13 8.33291 13.7781 7.34622 13.1188C6.35952 12.4595 5.59049 11.5225 5.13636 10.4261C4.68224 9.32975 4.56342 8.12335 4.79493 6.95946C5.02644 5.79558 5.59788 4.72648 6.437 3.88736C7.27611 3.04825 8.34521 2.4768 9.5091 2.24529C10.673 2.01378 11.8794 2.1326 12.9757 2.58673C14.0721 3.04085 15.0092 3.80989 15.6685 4.79658C16.3277 5.78328 16.6796 6.94332 16.6796 8.13C16.6796 9.7213 16.0475 11.2474 14.9223 12.3726C13.7971 13.4979 12.2709 14.13 10.6796 14.13Z\" fill=\"#fff\"\/><\/svg>\n\t\t\t\t\t<\/button>\n\n\t\t<button type=\"button\" class=\"practice-search-use-my-location\">\n\t\t\tSearch near me\n\t\t<\/button>\n\n\n\t<\/form>\n\n\n\n\t\t<\/div>\n\n\t\n<h2><b>What are eye charts?<\/b><\/h2>\n<p>Dr. Herman Snellen, a Dutch eye doctor, devised the first eye chart in 1862 to measure monocular and binocular visual acuity. Despite the existence of various eye charts, Snellen eye charts have remained the most common among eye care practitioners.<\/p>\n<h2><b>The Snellen eye chart<\/b><\/h2>\n<p>This letter chart design is most likely what you&#8217;re used to seeing at your eye doctor&#8217;s office.<\/p>\n<p>The Snellen eye chart starts with a single, large letter E at the top of the chart. Each line below gets incrementally smaller until the letters are so small that the only people who have better than 20\/20 vision can read them. The letter sizes are accurately determined to show perfect alignment to the 20\/20 scale&#8217;s visual norm.<\/p>\n<p>Even the types of letters used are carefully chosen. You\u2019ll notice, next time you look at an eye chart, not every letter of the alphabet is used. Only the letters C, D, E, F, L, N, O, P, T and Z. Some letters aren\u2019t used because they can easily be identified by the human brain even if they are too blurry to be seen clearly.<\/p>\n<p>For example, the letter Q. The brain is able to quickly pick up on the shadow of the tail that comes off that letter and determine what it is, since there is no other letter like it.<\/p>\n<p>In addition to the Snellen letter charts, there is also a Stellen image chart for children and adults who are unable to read.<\/p>\n<h2><b>What are eye charts used for?<\/b><\/h2>\n<p>Visual acuity \u2014\u00a0 how sharp your eyesight is \u2014 is measured using eye charts.<\/p>\n<p>Your ability to see the letters tells your optometrist whether you need glasses or contact lenses to improve your vision, or if your lens prescription needs to be changed.<\/p>\n<p>Your optometrist can create an accurate and customized lens prescription by analyzing the results of how clearly you see each line. Most routine eye exams, which are recommended every 1-2 years or as often as your optometrist suggests, use eye charts.<\/p>\n<p><strong>LEARN MORE:\u00a0<\/strong>\u00a0<a rel=\"noopener\" href=\"https:\/\/www.optometrists.org\/general-practice-optometry\/guide-to-eye-exams\/\" target=\"_blank\" data-saferedirecturl=\"https:\/\/www.google.com\/url?q=https:\/\/www.optometrists.org\/general-practice-optometry\/guide-to-eye-exams\/&amp;source=gmail&amp;ust=1626426910626000&amp;usg=AFQjCNF0g4kHSo2tmNbyXUe5jLhadUka6A\">Guide to Eye Exams<\/a><\/p>\n<p>If you feel your vision is not sharp,<a href=\"https:\/\/www.optometrists.org\/practice-search\/\"><b> schedule an eye exam<\/b><\/a> with an eye doctor near you, to see if you need prescription glasses or an updated prescription.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Did you know that the Snellen eye chart is the most commonly used chart during an eye exam? If you\u2019ve ever had an eye exam,<\/p>\n","protected":false},"author":4,"featured_media":12638,"parent":304,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"template-article.php","meta":{"footnotes":""},"categories":[],"tags":[],"class_list":["post-12637","page","type-page","status-publish","has-post-thumbnail","hentry"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v23.9 - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>Why Do Optometrists Use Eye Charts?\u00a0 - Optometrists.org<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/www.optometrists.org\/general-practice-optometry\/guide-to-eye-exams\/eye-exams\/why-do-optometrists-use-eye-charts\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Why Do Optometrists Use Eye Charts?\u00a0 - Optometrists.org\" \/>\n<meta property=\"og:description\" content=\"Did you know that the Snellen eye chart is the most commonly used chart during an eye exam? If you\u2019ve ever had an eye exam,\" \/>\n<meta property=\"og:url\" content=\"https:\/\/www.optometrists.org\/general-practice-optometry\/guide-to-eye-exams\/eye-exams\/why-do-optometrists-use-eye-charts\/\" \/>\n<meta property=\"og:site_name\" content=\"Optometrists.org\" \/>\n<meta property=\"article:modified_time\" content=\"2021-07-15T09:16:53+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/www.optometrists.org\/wp-content\/uploads\/2021\/06\/chart.jpg\" \/>\n\t<meta property=\"og:image:width\" content=\"150\" \/>\n\t<meta property=\"og:image:height\" content=\"224\" \/>\n\t<meta property=\"og:image:type\" content=\"image\/jpeg\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data1\" content=\"3 minutes\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":\"WebPage\",\"@id\":\"https:\/\/www.optometrists.org\/general-practice-optometry\/guide-to-eye-exams\/eye-exams\/why-do-optometrists-use-eye-charts\/\",\"url\":\"https:\/\/www.optometrists.org\/general-practice-optometry\/guide-to-eye-exams\/eye-exams\/why-do-optometrists-use-eye-charts\/\",\"name\":\"Why Do Optometrists Use Eye Charts?\u00a0 - Optometrists.org\",\"isPartOf\":{\"@id\":\"https:\/\/www.optometrists.org\/#website\"},\"primaryImageOfPage\":{\"@id\":\"https:\/\/www.optometrists.org\/general-practice-optometry\/guide-to-eye-exams\/eye-exams\/why-do-optometrists-use-eye-charts\/#primaryimage\"},\"image\":{\"@id\":\"https:\/\/www.optometrists.org\/general-practice-optometry\/guide-to-eye-exams\/eye-exams\/why-do-optometrists-use-eye-charts\/#primaryimage\"},\"thumbnailUrl\":\"https:\/\/www.optometrists.org\/wp-content\/uploads\/2021\/06\/chart.jpg\",\"datePublished\":\"2021-06-09T06:35:06+00:00\",\"dateModified\":\"2021-07-15T09:16:53+00:00\",\"breadcrumb\":{\"@id\":\"https:\/\/www.optometrists.org\/general-practice-optometry\/guide-to-eye-exams\/eye-exams\/why-do-optometrists-use-eye-charts\/#breadcrumb\"},\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\/\/www.optometrists.org\/general-practice-optometry\/guide-to-eye-exams\/eye-exams\/why-do-optometrists-use-eye-charts\/\"]}]},{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\/\/www.optometrists.org\/general-practice-optometry\/guide-to-eye-exams\/eye-exams\/why-do-optometrists-use-eye-charts\/#primaryimage\",\"url\":\"https:\/\/www.optometrists.org\/wp-content\/uploads\/2021\/06\/chart.jpg\",\"contentUrl\":\"https:\/\/www.optometrists.org\/wp-content\/uploads\/2021\/06\/chart.jpg\",\"width\":150,\"height\":224},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\/\/www.optometrists.org\/general-practice-optometry\/guide-to-eye-exams\/eye-exams\/why-do-optometrists-use-eye-charts\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\/\/www.optometrists.org\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"Primary Eye Care\",\"item\":\"https:\/\/www.optometrists.org\/general-practice-optometry\/\"},{\"@type\":\"ListItem\",\"position\":3,\"name\":\"Guide to Eye Exams\",\"item\":\"https:\/\/www.optometrists.org\/general-practice-optometry\/guide-to-eye-exams\/\"},{\"@type\":\"ListItem\",\"position\":4,\"name\":\"Eye Exams\",\"item\":\"https:\/\/www.optometrists.org\/general-practice-optometry\/guide-to-eye-exams\/eye-exams\/\"},{\"@type\":\"ListItem\",\"position\":5,\"name\":\"Why Do Optometrists Use Eye Charts?\u00a0\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\/\/www.optometrists.org\/#website\",\"url\":\"https:\/\/www.optometrists.org\/\",\"name\":\"Optometrists.org\",\"description\":\"\",\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\/\/www.optometrists.org\/?s={search_term_string}\"},\"query-input\":{\"@type\":\"PropertyValueSpecification\",\"valueRequired\":true,\"valueName\":\"search_term_string\"}}],\"inLanguage\":\"en-US\"}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"Why Do Optometrists Use Eye Charts?\u00a0 - Optometrists.org","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/www.optometrists.org\/general-practice-optometry\/guide-to-eye-exams\/eye-exams\/why-do-optometrists-use-eye-charts\/","og_locale":"en_US","og_type":"article","og_title":"Why Do Optometrists Use Eye Charts?\u00a0 - Optometrists.org","og_description":"Did you know that the Snellen eye chart is the most commonly used chart during an eye exam? If you\u2019ve ever had an eye exam,","og_url":"https:\/\/www.optometrists.org\/general-practice-optometry\/guide-to-eye-exams\/eye-exams\/why-do-optometrists-use-eye-charts\/","og_site_name":"Optometrists.org","article_modified_time":"2021-07-15T09:16:53+00:00","og_image":[{"width":150,"height":224,"url":"https:\/\/www.optometrists.org\/wp-content\/uploads\/2021\/06\/chart.jpg","type":"image\/jpeg"}],"twitter_card":"summary_large_image","twitter_misc":{"Est. reading time":"3 minutes"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"WebPage","@id":"https:\/\/www.optometrists.org\/general-practice-optometry\/guide-to-eye-exams\/eye-exams\/why-do-optometrists-use-eye-charts\/","url":"https:\/\/www.optometrists.org\/general-practice-optometry\/guide-to-eye-exams\/eye-exams\/why-do-optometrists-use-eye-charts\/","name":"Why Do Optometrists Use Eye Charts?\u00a0 - Optometrists.org","isPartOf":{"@id":"https:\/\/www.optometrists.org\/#website"},"primaryImageOfPage":{"@id":"https:\/\/www.optometrists.org\/general-practice-optometry\/guide-to-eye-exams\/eye-exams\/why-do-optometrists-use-eye-charts\/#primaryimage"},"image":{"@id":"https:\/\/www.optometrists.org\/general-practice-optometry\/guide-to-eye-exams\/eye-exams\/why-do-optometrists-use-eye-charts\/#primaryimage"},"thumbnailUrl":"https:\/\/www.optometrists.org\/wp-content\/uploads\/2021\/06\/chart.jpg","datePublished":"2021-06-09T06:35:06+00:00","dateModified":"2021-07-15T09:16:53+00:00","breadcrumb":{"@id":"https:\/\/www.optometrists.org\/general-practice-optometry\/guide-to-eye-exams\/eye-exams\/why-do-optometrists-use-eye-charts\/#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/www.optometrists.org\/general-practice-optometry\/guide-to-eye-exams\/eye-exams\/why-do-optometrists-use-eye-charts\/"]}]},{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/www.optometrists.org\/general-practice-optometry\/guide-to-eye-exams\/eye-exams\/why-do-optometrists-use-eye-charts\/#primaryimage","url":"https:\/\/www.optometrists.org\/wp-content\/uploads\/2021\/06\/chart.jpg","contentUrl":"https:\/\/www.optometrists.org\/wp-content\/uploads\/2021\/06\/chart.jpg","width":150,"height":224},{"@type":"BreadcrumbList","@id":"https:\/\/www.optometrists.org\/general-practice-optometry\/guide-to-eye-exams\/eye-exams\/why-do-optometrists-use-eye-charts\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/www.optometrists.org\/"},{"@type":"ListItem","position":2,"name":"Primary Eye Care","item":"https:\/\/www.optometrists.org\/general-practice-optometry\/"},{"@type":"ListItem","position":3,"name":"Guide to Eye Exams","item":"https:\/\/www.optometrists.org\/general-practice-optometry\/guide-to-eye-exams\/"},{"@type":"ListItem","position":4,"name":"Eye Exams","item":"https:\/\/www.optometrists.org\/general-practice-optometry\/guide-to-eye-exams\/eye-exams\/"},{"@type":"ListItem","position":5,"name":"Why Do Optometrists Use Eye Charts?\u00a0"}]},{"@type":"WebSite","@id":"https:\/\/www.optometrists.org\/#website","url":"https:\/\/www.optometrists.org\/","name":"Optometrists.org","description":"","potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/www.optometrists.org\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"en-US"}]}},"_links":{"self":[{"href":"https:\/\/www.optometrists.org\/wp-json\/wp\/v2\/pages\/12637","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.optometrists.org\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www.optometrists.org\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www.optometrists.org\/wp-json\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/www.optometrists.org\/wp-json\/wp\/v2\/comments?post=12637"}],"version-history":[{"count":0,"href":"https:\/\/www.optometrists.org\/wp-json\/wp\/v2\/pages\/12637\/revisions"}],"up":[{"embeddable":true,"href":"https:\/\/www.optometrists.org\/wp-json\/wp\/v2\/pages\/304"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.optometrists.org\/wp-json\/wp\/v2\/media\/12638"}],"wp:attachment":[{"href":"https:\/\/www.optometrists.org\/wp-json\/wp\/v2\/media?parent=12637"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.optometrists.org\/wp-json\/wp\/v2\/categories?post=12637"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.optometrists.org\/wp-json\/wp\/v2\/tags?post=12637"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}