{"id":4543,"date":"2026-10-01T07:03:00","date_gmt":"2026-10-01T05:03:00","guid":{"rendered":"https:\/\/www.eyemark.co.za\/vision-newsletters\/?p=4543"},"modified":"2026-10-01T07:11:59","modified_gmt":"2026-10-01T05:11:59","slug":"the-eye-brain-connection","status":"publish","type":"post","link":"https:\/\/www.eyemark.co.za\/vision-newsletters\/2026\/10\/the-eye-brain-connection\/","title":{"rendered":"THE EYE-BRAIN CONNECTION"},"content":{"rendered":"\n

\u201cThe eye sees all, but the mind shows us what we want to see\u201d. (William Shakespeare)<\/em><\/p>\n\n\n\n

Approximately 80% of everything we learn comes through the eyes. While the eye is the organ of sight, it is in the brain that sight becomes vision. In the brain we make sense of the information we receive from the eyes, attach meaning to it and respond to it. Vision is dependent on the connection between the eyes and the brain and relies as much on the brain as it does on our eyes. It has been said that the brain begins inside the eye and that the retina is the starting point for processing visual information. The retina itself develops from the same tissue as the brain and is considered part of the central nervous system. It is a key bridge between the light that enters our eyes and the images we see.<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

In order for us to see, light rays entering the eyes must be bent, or refracted and follow a specific process before they can focus directly on the retina at the back of the eye. Light enters the eye through the cornea where it is refracted and then passes through the pupil to the lens. The pupil automatically adjusts to the intensity of the light by becoming larger or smaller. The lens changes its shape to bend the light a second time. Having passed through the clear gelatinous layer, the vitreous, it reaches the retina where it is picked up by millions of photoreceptors, which convert the light waves into electrical impulses. These travel via the optic nerve to the brain. While the light is focused throughout the retina, most of the light entering the eye is focused onto the focal point on the retina, the macula.<\/p>\n\n\n\n

One layer of the retina is brain tissue which begins coding visual information even before messages are sent via the optic nerve to the brain. Another layer is made up of blood vessels which need the oxygen from a good aerobic workout.<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

An estimated 125 million photoreceptors, specialised light-sensitive nerve cells called rods and cones, begin processing visual information.<\/p>\n\n\n\n

Rods are particularly important in peripheral vision and conditions of dim light, as they help the eyes gather light.<\/p>\n\n\n\n

Cones work in bright light and help us see colour and fine detail. There are three different kinds of cones, each sensitive to a different colour, red, green or blue. The brain mixes the messages from these cones so that we can see all colours. Cones are less effective in the dark, which is why it\u2019s difficult to see colour at night.<\/p>\n\n\n\n

Other retinal cells analyse information such as contrast, shape, movement and changes in brightness.<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

The electrical impulses leave the retina through an opening called the optic disc. Once leaving the retina, they become known as the optic nerve, a cable-like collection of nerve fibres that connects and transmits visual information from the eye to the brain. As the optic nerve has no photoreceptors, visual information cannot be processed, resulting in a natural blind spot in each eye. We don\u2019t notice this gap in our vision because the brain relies on the other eye and surrounding photoreceptors to fill in the missing information.<\/p>\n\n\n\n

Because the light has been bent twice, once as it moves through the cornea and the other through the lens, the image projected onto the retina is upside down and reversed. The visual system in the brain interprets this incoming information and produces the stable, correctly orientated world that we experience.<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

One of its key characteristics is that the retina has been described as the window to our general health, making a retinal examination considerably more than a vision examination.<\/p>\n\n\n\n

The retina is one of the few places in the body where an eyecare professional can directly observe blood vessels relatively easily and non-invasively. The tiny blood vessels in the eyes can provide clues about what may be happening elsewhere in your body.<\/p>\n\n\n\n

As well as alerting your optometrist to eye disease, changes in retinal blood vessels may be associated with conditions such as diabetes and high blood pressure, often before symptoms have appeared. Early diagnosis and treatment of health conditions in the eyes and body may help slow or stop the progression of the condition and help prevent irreversible damage.<\/p>\n\n\n\n

So, the retina may be thought of as a sophisticated biological processor, health-monitoring window and outpost of the brain, all packed into a layer of tissue at the back of an eye.<\/p>\n","protected":false},"excerpt":{"rendered":"

\u201cThe eye sees all, but the mind shows us what we want to see\u201d. (William Shakespeare) Approximately 80% of everything we learn comes through the eyes. While the eye is the organ of sight, it is in the brain that sight becomes vision. In the brain we make sense of the information we receive from […]<\/p>\n","protected":false},"author":3,"featured_media":4530,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"set","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"categories":[44,59],"tags":[],"post_folder":[],"class_list":["post-4543","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-44","category-2026-10"],"_links":{"self":[{"href":"https:\/\/www.eyemark.co.za\/vision-newsletters\/wp-json\/wp\/v2\/posts\/4543","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.eyemark.co.za\/vision-newsletters\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.eyemark.co.za\/vision-newsletters\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.eyemark.co.za\/vision-newsletters\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/www.eyemark.co.za\/vision-newsletters\/wp-json\/wp\/v2\/comments?post=4543"}],"version-history":[{"count":10,"href":"https:\/\/www.eyemark.co.za\/vision-newsletters\/wp-json\/wp\/v2\/posts\/4543\/revisions"}],"predecessor-version":[{"id":4554,"href":"https:\/\/www.eyemark.co.za\/vision-newsletters\/wp-json\/wp\/v2\/posts\/4543\/revisions\/4554"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.eyemark.co.za\/vision-newsletters\/wp-json\/wp\/v2\/media\/4530"}],"wp:attachment":[{"href":"https:\/\/www.eyemark.co.za\/vision-newsletters\/wp-json\/wp\/v2\/media?parent=4543"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.eyemark.co.za\/vision-newsletters\/wp-json\/wp\/v2\/categories?post=4543"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.eyemark.co.za\/vision-newsletters\/wp-json\/wp\/v2\/tags?post=4543"},{"taxonomy":"post_folder","embeddable":true,"href":"https:\/\/www.eyemark.co.za\/vision-newsletters\/wp-json\/wp\/v2\/post_folder?post=4543"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}