Eye Effects in Calgary & Didsbury
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Understanding the Human Eye

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The eye is a fascinating organ, made up of many different parts which all work together with the brain to provide sight. Much like a digital camera, when one part isn’t functioning well, images can be blurry or not even get transmitted to the visual cortex. An annual eye exam protects your vision and looks for potential health problems, such as glaucoma, high blood pressure, or diabetes. Don’t overlook this vital assessment to know your eye health.

The Parts of Your Eye

labeled diagram of the human eye
The eye is a fascinating organ, made up of many different tissues and fluids, all working together to convert light into neurological data — to produce what we experience as sight. Your eyes capture and convert images a lot like a digital camera.
Just like the sensitive camera technology in your smartphone, when one component of your eye experiences a problem, the rest of the functionality is at risk. Images can easily get lost or distorted before they’re transmitted to the visual cortex.
Annual eye exams for adults, seniors, and children provide the benefit of finding potential eye health problems like glaucoma, macular degeneration, or diabetic retinopathy. Prevention is possible through early detection and your optometrist’s trained eye.

Ocular Orbit & Sclera

It helps to start on the fringes of the eye to understand it. The orbit is the bony opening in the skull, circular in shape to accommodate it. Connected to the orbit are 6 extraocular muscles that control where the eye points. These muscles also attach to the outside of your eyeball, a white tissue called the sclera.

Lacrimal Gland

Also nestled near the orbit lies the lacrimal gland. It produces tears and sends them through ducts in your upper eyelids for hydration and oxygenation.

Conjunctiva & Tear Film

 But on top of the sclera is a transparent membrane called the conjunctiva. Your conjunctiva can be affected by conjunctivitis. The tear film and the conjunctiva are the parts of your eyes that brave the elements. Your tear film is a mix of oil, water, and mucous helped along by the meibomian and lacrimal glands (and mucin goblet cells at the conjunctiva). If you have dry eye, this mixture will have a low level or imbalanced composition.


Your bottom eyelids aren’t part of your eye, but they also have conjunctiva coating the part that slips over your eye. In them, they house multiple meibomian glands. Dry eye therapy can help if your tear film is a bit off. If it goes untreated, dry eye can damage and distort the cornea.


Your cornea is a transparent tissue a bit like skin, ideally forming an even dome over your pupil. As mentioned, it’s covered by the tear film for moisture and oxygenation since it has no blood vessels running through it.
The cornea is another focal point we pay special attention to. If your cornea has an irregular shape, myopia, hyperopia, or astigmatism are likely diagnoses. In that case, you’ll need glasses and prescription sunglasses to correct your vision while indoors and outdoors. We also recommend contact lenses, but we’ll need to do a contact lens fitting and exam to ensure they’ll fit adequately while correcting your vision.

Reshaping Cornea

A misshapen cornea can also undergo surgery to even it out, most often for patients with more conical corneas. Laser eye surgeries come with a few different procedures, but what they have in common is targeting and vaporizing parts of your cornea. This surgery needs careful vetting and preparation because not everyone stands the same chance at a full recovery. If you need some help determining whether it’s right for you, you can rely on laser eye surgery consultation.
As long as all is well with your cornea, your optometrist will next look at your pupils and irises. We don’t often encounter problems here, but we check anyway.

Iris & Pupil

The iris gives your eyes colour, but this part of your eye also changes shape to control the amount of light that enters your eye through the pupil. The iris actually expands and contracts, contracting to cover the pupil with its often melanin-rich tissue (in the case of people with brown eyes, that is). In light-eyed people, the tissue is actually clear, so it lets a bit of light through. Blue light wavelengths within white light scatter and bend all over because the structure of the iris makes for a refractive barrier at the blue light wavelength, giving people the appearance of blue eyes. Green eyes are actually partially pigmented with melanin, so scattering blue light and brown melanin particles interspersed together give the appearance of the colour green.
Behind the iris is a dark circle, the pupil. The pupil interacts with the iris to filter light into your ocular lens. Like a camera lens, your ocular lens further bends images (essentially light patterns) to a small spot at the back of the eye. This lens is sensitive to UV light. Its tissues are susceptible to cataracts in your older years, given enough accumulated UV exposure.

Aqueous Humour & Vitreous Body

Your eye’s interior is made up of a clear fluid call the aqueous humour and a jelly-like substance called the vitreous body. These substances provide the structure of the eye. Sometimes, what we called floaters become noticeable. They’re actually shedding-cells floating in the vitreous body, casting shadows onto the back of your eye. What you see is the shadow.

Retina & Optic Nerve

Your retina is a crucial part of your eye, and its delicate parts need to be checked on to preserve your vision for your golden years. The retina changes the light into neural signals, then transmitted to the brain through the optic nerve. The retina is a cellular membrane covering the back of the eye, and its function is to photograph light. Think of your TV screen. To make colours, red, green, and blue pinpoints in the screen intersperse to make larger colours and blends. Special cells resembling rods and cones are interspersed throughout your retina so your eye can turn images (i.e., coloured patterns of light) into synchronized nervous system data. That data transfers from your retina into your brain through the optic nerve. With this data conversion, the retina processes what you see and renders an image in your brain. 

Macula & Fovea

Within your retina is the high-definition macula, which is responsible for high-acuity vision. Details like faces and text require much more sensitive rods and cones, so this little point in your retina becomes the make-or-break image detection center. The fovea is an even more sensitive component of the macula for high-def vision. Your optometrist will always scrutinize this area, especially for diabetic patients who’s maculae are at risk.

Eye Exams & Retinal Imaging

There are even more parts to your eye than that! At our eye exams for adults, seniors, and children, we scan all accessible parts of your eye for any irregularities to keep it in top form for the next year. Technology like OCT imaging has made treating the delicate and complex parts of the eye much easier. An eye doctor can more easily see into the back of the eye — inspecting the retina when your pupils are dilated at an extensive angle with robust magnification. This equipment and procedure gives them significant clues about your eye condition. Make sure you get an annual eye exam to keep your vision in peak condition. Early diagnosis can often slow down the signs of aging and prevent sight loss due to disease. Protect your health with an appointment if you’re in Calgary or Didsbury.

Written by Dr. Rod Adams

Dr. Rod Adams is a graduate of the University of Alberta and the University of California at Berkeley School of Optometry. Dr. Adams has been in private family practice since 1997. During this time, he has developed a strong interest in pediatric optometry and laser corrective surgery options.
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