Generic selectors
Exact matches only
Search in title
Search in content
Post Type Selectors
Search in posts
Search in pages
Generic selectors
Exact matches only
Search in title
Search in content
Post Type Selectors
Search in posts
Search in pages

How the Eye Works

  • 26 October, 2023

    How the Eye Works

    The human eye, a marvel of nature, is often taken for granted. With its intricate structure and functions, the eye provides us with the ability to perceive the world around us. Let’s dive deep into understanding how the eye works, how light interacts with various parts of the eye, and the importance of each component.

    The Journey of Light: From the Outside to the Inside

    Light Enters the Eye

    When we look at an object, light waves from that object enter the eye. The first part of the eye it encounters is the cornea, which is the clear window at the front of the eye. This transparent and curved layer works to focus light, directing it towards the pupil, the black circle in the centre of the colourful part of the eye, known as the iris.

    Role of the Iris and Pupil in Regulating Light

    The iris, the coloured part of the eye, functions like a camera aperture. It adjusts the size of the pupil, determining how much light enters the eye. In bright light, the pupil constricts, and in low light, it dilates (gets bigger!). This mechanism ensures that the optimal amount of light passes through to the back of the eye.

    Journey Through the Lens

    Past the iris, light enters the lens, which works to further focus light. Positioned behind the iris, the lens works dynamically. It changes shape, aided by the ciliary body, to ensure that light rays converge at the right focal point on the retina, the light sensitive membrane lining the back of the eye.

    The Vitreous Chamber and Humours

    The Vitreous Chamber and Humours

    Once the light passes through the lens, it travels through the vitreous humour, or vitreous body, a jelly-like substance filling the posterior chamber of the eye. The anterior chamber, located between the cornea and iris, is filled with a clear liquid called the aqueous humour. These humours play an important role in maintaining the eye’s shape and ensuring a clear image on the retina.

    The Retina: Where Light Becomes Vision

    The retina, the light sensitive layer at the back of the eye, houses the special photoreceptor cells, which include rods and cones. These cells are sensitive to light and play a crucial role in vision.

    Rods, Cones, and Retinal Pigment Epithelium

    • Rods: These cells are highly sensitive to light, allowing us to see in low light conditions. However, they don’t detect colour, contributing more to our peripheral vision.
    • Cones: Cone cells enable colour vision and help us see fine details. They’re central to our central vision.
    • Retinal pigment epithelium (RPE): Beneath the retina lies the retinal pigment epithelium, a layer crucial for nourishing the photoreceptor cells. The intricate network of blood vessels present in the choroid just below the RPE plays a pivotal role in supplying the retina with nutrients.

    Electrical Impulses and the Optic Nerve

    When light rays strike the rods and cones, they generate electrical impulses. These impulses are then gathered by nerve fibres and transmitted to the optic nerve. The optic nerve serves as a bridge, carrying visual information from the eye to the visual cortex in the brain. Interestingly, the point where the optic nerve exits the retina creates a ‘blind spot’, as no visual cells are present there.

    How Our Brain Interprets Vision

    After the electrical impulses reach the brain, the visual cortex processes this information, allowing us to perceive the object we’re looking at. The brain’s ability to interpret these signals and give them meaning is what truly makes vision complete.

    Potential Vision Problems

    While the human eye is brilliantly designed, it’s not free from imperfections. Blurred vision occurs when light doesn’t focus correctly on the retina. This could be due to the shape of the cornea, lens, or even the length of the eyeball. In some cases, corrective lenses can help the eye focus light correctly. Please find a list of common visual conditions:

    • Astigmatism: A common vision condition caused by an imperfection in the curvature of the cornea or lens. Instead of one focal point on the retina, there are multiple, resulting in blurred or distorted vision at all distances.
    • Myopia (Shortsightedness): When the eyeball is too long or the cornea has too much curvature, it causes myopia. This means distant objects appear blurry while close objects can be seen clearly.
    • Presbyopia: An age-related condition where the eye’s lens loses its flexibility, making it difficult to focus on close-up objects. This often becomes noticeable in the early to mid-40s.
    • Lazy Eye (Amblyopia): A vision development disorder where one eye doesn’t achieve normal visual acuity, even with prescription eyeglasses or contact lenses. It usually begins during infancy or early childhood.
    • Cataracts: A clouding of the usually clear lens of the eye, often leading to a decrease in vision. It typically progresses slowly and can affect one or both eyes.
    • Dry Eye: This condition arises when tear glands don’t produce enough tears or produce poor-quality tears, leading to dryness, itching, redness, and blurred vision.
    • Age-related Macular Degeneration (AMD): A condition where the central part of the retina (known as the macula) degenerates, leading to blurred, distorted or a loss of central vision.
    • Glaucoma: Is a condition in which increased pressure within the eye damages the nerve cells leading to a loss of peripheral or side vision.

    There are numerous eye conditions, from cataracts affecting the lens to retinal issues such as Age-Related Macular Degeneration (AMD) affecting the light sensitive membrane. Regular check-ups can help with early detection and treatment.

    For a deeper dive into these and other conditions, as well as potential treatments and preventative measures, click here to learn more about various eye conditions.

    Eye Exam

    Prioritising Vision with Expert Care

    From the moment light enters the clear layer at the front of the eye to when the brain processes it, our eyes work in a synchronised manner, turning light waves into meaningful images. While this overview provides a solid understanding of how the eye works, there’s still much to explore, especially regarding eye conditions and how various parts of the body work together to preserve vision.

    Understanding and taking care of this intricate organ requires specialised knowledge and care. This is where professional eyecare is vital.

    Embracing Excellence: EyeQ Optometrists’ Commitment to Lifelong Vision Care

    At EyeQ Optometrists, we pride ourselves on being true experts in eye care. With state-of-the-art equipment and a network of trained professionals who undergo consistent training, EyeQ ensures that we remain at the forefront of clinical diagnosis and treatment. What sets us apart is our relentless drive to provide personalised care tailored to every patient’s unique needs. From infancy to old age, we’re determined to look after your eyes for life.

    Your eyes aren’t just a window to the world; they’re a window to your overall health. Regular eye check-ups can help detect potential problems early on, ensuring that your vision remains clear and healthy.

    Whether you’re simply curious or seeking to understand a specific eye condition, always remember that the human eye is a remarkable organ, worth every bit of our appreciation and care. And when it comes to entrusting someone with its care, why not go with the best in the field? Find an EyeQ optometrist near you and book an eye test today. Embrace the assurance of expert care, because looking after your eyes means looking after your life.

    • Share It


Our contact lens provider Alcon is experiencing delays fulfilling orders due to a cyber-security incident involving their freight partner, Toll Group. These delays are across their entire network of optical retailers in Australia. We apologise for an inconvenience caused and encourage you to contact your local EyeQ practice for any urgent requirements.