Our office at the Four Corners Medical Arts Centre is located in the South-end of Sudbury. We have state-of-the-art equipment and technicians on-site, an eyewear gallery with a great selection of classic and contemporary styles.  
   
     
     
 
Four Corners Medical Arts Centre
2009 Long Lake Road, Suite 105
Sudbury, Ontario P3E 6C3
Tel. 705.675.2554
Fax: 705.675.2546
Email: eyedocs@eyedocs.ca
 
     
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HOW THE EYE WORKS

Our ability to "see" starts when light reflects off an object at which we are looking and enters the eye. As it enters the eye, the light is unfocused. The first step in seeing is to focus the light rays onto the retina, which is the light sensitive layer found inside the eye. Once the light is focused, it stimulates cells to send millions of electrochemical impulses along the optic nerve to the brain. The portion of the brain at the back of the head interprets the impulses, enabling us to see the object.

Light, refraction and its importance.

Light entering the eye is first bent, or refracted, by the cornea -- the clear window on the outer front surface of the eyeball. The cornea provides most of the eye's optical power or light-bending ability.

After the light passes through the cornea, it is bent again -- to a more finely adjusted focus -- by the crystalline lens inside the eye. The lens focuses the light on the retina. This is achieved by the ciliary muscles in the eye changing the shape of the lens, bending or flattening it to focus the light rays on the retina.

This adjustment in the lens, known as accommodation, is necessary for bringing near and far objects into focus. The process of bending light to produce a focused image on the retina is called "refraction". Ideally, the light is "refracted," or redirected, in such a manner that the rays are focused into a precise image on the retina.

Most vision problems occur because of an error in how our eyes refract light. In nearsightedness (myopia), the light rays form an image in front of the retina. In farsightedness (hypermetropia), the rays focus behind the retina. In astigmatism, the curvature of the cornea is irregular, causing light rays to focus to more than one place so that a single clear image cannot be formed on the retina, resulting in blurred vision. As we age, we find reading or performing close-up activities more difficult. This condition is called presbyopia, and results from the crystalline lens being less flexible, and therefore less able to bend light.

Since changing the apparent refraction of the eye is relatively easy through the use of corrective spectacle or contact lenses, many of the conditions that contribute to unclear vision can be readily corrected.

How do we make sense of light?

Sensory interpretation
Even with the light focused on the retina, the process of seeing is not complete. For one thing, the image is inverted, or upside down. Light from the various "pieces" of the object being observed stimulate nerve endings -- photoreceptors or cells sensitive to light -- in the retina.

Rods and cones
Two types of receptors -- rods and cones -- are present. Rods are mainly found in the peripheral retina and enable us to see in dim light and to detect peripheral motion. They are primarily responsible for night vision and visual orientation. Cones are principally found in the central retina and provide detailed vision for such tasks as reading or distinguishing distant objects. They also are necessary for color detection. These photoreceptors convert light to electrochemical impulses that are transmitted via the nerves to the brain.

Millions of impulses travel along the nerve fibers of the optic nerve at the back of the eye, eventually arriving at the visual cortex of the brain, located at the back of the head. Here, the electrochemical impulses are unscrambled and interpreted. The image is re-inverted so that we see the object the right way up. This "sensory" part of seeing is much more complex than the refractive part -- and therefore is much more difficult to influence accurately.

Vision and Aging

Vision and Aging: A guide to good eye health and vision
Eyes often benefit from having more than one pair of prescription eyewear to meet special vision requirements. Your optometrist understands the special demands of aging and will offer specific recommendations so you can enjoy clear and comfortable vision.

As your golden years approach, it is especially important to make regular eye examinations part of your plan for maintaining good health and vision.

As you age, there are a few common conditions you and your optometrist need to look for. There’s nothing uncommon about noticing changes in your vision.

Here is a short list of the most common and troubling conditions:

Presbyopia is very common among this age group. It is the loss of ability to change focus from far to near. It is often the first wake-up call that our eyes "aren’t what they used to be". The most common signs or symptoms include the tendency to hold reading materials at arm’s length, blurred vision at normal reading distance and eye fatigue when attempting to do close work. For more information, click here.

Glaucoma can result when excessive fluid pressures damage the optic nerve. It is one of the leading causes of blindness in Canada. Glaucoma can be effectively treated with prescription eye drops, and in some cases, surgery may be required. A simple and painless procedure allows your optometrist to measure the internal pressures of your eye. Early detection is the key to success when fighting glaucoma. Most glaucomas offer no pain or symptoms. For more information, click here.

Cataracts are another common condition you may encounter. Cataracts occur as the lens becomes cloudy, distorting our vision. Cataracts are most often found in persons over the age of 55, but can occur in younger people as well. This condition often requires a corrective lens change or surgical removal. After surgery, you, along with your Optometrist, can decide on the best type of vision correction for you. For more information, click here.

Macular Degeneration is a disease that obscures a person’s central field of vision.
It is the leading cause of vision loss and blindness for seniors in North America. Early detection is the key to managing the disease – that’s why yearly exams with your Optometrist are recommended. For more information, click here.

The value of prevention… Health, nutrition and prevention are the keys to quality of life. Maintaining excellent general health can often delay and reduce the effects of aging on our eyes.

Even with the best preventative efforts, some changes in our vision should be expected. There is often a greater need to rely on glasses for tasks such as reading. Special filters and sunglasses can also help with problems associated with glare or light sensitivity. Extra lighting or special magnification may be helpful for people with reduced or low vision.

Several common health conditions, such as high blood pressure, arthritis and diabetes often require medications – some of which affect the eyes and vision. In their early stages, many conditions associated with aging may not cause symptoms or create problems, and therefore, can go undetected. Regular optometric care is vital.

Your optometrist understands the changes in your eyesight, the importance of early detection in eye disease and the implications of medications you may be taking. Annual eye health assessments are important to identify your individual needs, assist you in understanding your conditions, and allow your eye doctor to make specific recommendations for you.

Did You Know?

When it comes to your eyes and your vision, expect to experience some signs of aging as you near your 40th birthday. Now before you start feeling old before your time, relax.

Your optometrist will help you manage these natural changes in your vision, and monitor your eye health at the same time!

Optometrists are specially trained to help you as your eyes get older and can expertly prescribe eyewear that will allow you to maintain your best possible focus at any distance. You may need reading glasses, or some form of multi-focals, bi-focals, tri-focals or progressive lenses. Today’s eyewear is stylish, comfortable and easy to wear. There are even contact lenses available in multi-focal form for some prescriptions.

Vitamins / Nutrition *

Many optometrists are expanding their traditional role to include other areas that affect eye health, such as nutrition. Research has shown that nutrition can impact the development of cataracts and age-related macular degeneration (AMD), which are the two leading causes of blindness and visual impairment among millions of aging Americans. Nutrition may be particularly important given that currently, treatment options after diagnosis for these eye diseases are limited.

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