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Why Do We Need Glasses?

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The most well-known part of a comprehensive eye exam is the basic vision test. When you have a general vision test, one of the main conditions the eye care practitioner is checking for is a refractive error. A refractive error means there is an abnormality in the shape of the eye, changing the eye’s ability to focus light directly onto the retina.This causes blurred vision and can usually be corrected by wearing prescription eyeglasses, contact lenses and possibly, alternate treatments such as vision therapy, ortho-k, LASIK or refractive surgery such as LASIK.

The term, “refractive error” refers to a problem with the process of refraction that is responsible for sight. Normally, light rays that enter your eye are refracted or bent through the cornea and the lens, and ultimately converge or are focused onto a single point on the retina. From the retina, messages are sent through the optic nerve to the brain which then interprets these signals into the image that we are seeing.   

In order for this process to work effectively, the anatomy of the eye including the length of the eye and the curvature of the cornea and the lens must be just right to be able to focus the light onto the retina. When this is not the case, a refractive error will occur.

There are several different types of refractive errors, depending on which part of the eye is affected, and it is possible to have multiple refractive errors at the same time:  

 

Myopia or nearsightedness:

In myopia the length of the eyeball is too long which results in light coming to a focus in front of the retina, rather than on the retina. This allows the individual to see well when objects are close but not clearly when looking at objects at a distance.

Hyperopia or farsightedness:

Hyperopia is when the eyeball is shorter than normal and can result in near objects being blurry. However, people experience hyperopia differently. Sometimes distant objects are clear while other times people may experience overall blurred vision near and far or no problems at all. In children particularly, the lens may accommodate for the error allowing for clear vision but may cause fatigue and sometimes crossed eyes or strabismus. Hyperopia causes eyestrain or fatigue especially when looking at near objects for a period of time. Often people with 20/20 vision may still need glasses at their desk to relax their eyes and improve concentration.

Astigmatism:

Astigmatism is usually the result of an irregularly shaped cornea (although it can sometimes also be due to a misshapen lens). The cornea, which is normally round, is more football-shaped in an eye with astigmatism, resulting in multiple focus points either in front of the retina or behind it (or both). People with astigmatism usually have blurred or distorted vision to some degree at all distances, near and far.

 

Presbyopia:

Presbyopia is an age-related condition which usually begins to appear sometime after 40.  As the eye begins to age, the lens stiffens and can no longer focus clearly on objects that are close.  

It’s important to note that presbyopia is often confused with hyperopia, as both cause problems focusing at near distances.  However, high hyperopia can also cause blur at far distances as well, especially in dim lighting, and depth perception problems can result in motor vehicle accidents.  In these instances people with hyperopia could use glasses at any distance.

If you are having trouble seeing, it is important to have an eye exam to determine the cause of the problem and to effectively correct your vision. Even if your vision is fine, you should schedule a routine eye exam on a regular basis to ensure that your eyes are healthy and that any potential problems are caught early.

 

Thank you for trusting your eyecare with us over the years.  The Foresight Eyecare team follows the government mandate to reduce the spread of the COVID-19 pandemic.  After December 2020 announcements made by the Alberta Government, our clinic is following the revised Infection Prevention and Control policy by the Alberta College of Optometrists.

Patients interested in obtaining eye exam services or eye care products can be seen by appointment only.  Please call ahead, and staff will arrange an appointment time and ask COVID-19 screening questions.  If you have any symptoms of cough, fever, runny nose or shortness of breath, we ask that you call or e-mail us and do not attend the clinic for your scheduled visit.   Within the clinic, please wear a mask and use the hand sanitizer at reception.  Our clinic complies with the City of Calgary bylaw requiring mask covering over the age of two years old.  For patients who are unable to wear a face covering due to medical reasons, the patient can be scheduled for an appointment at a time when minimal number of other patients are in the clinic such as at the beginning or end of the day to ensure appropriate physical distancing requirements.

We are using disposable disinfectant wipes on all surfaces and devices such as front desk counters, chairs, handles in exam rooms and waiting room.  All eyewear that have been touched by patients are continually being sanitized.   Any toys and magazines are stored at this time.  Examination areas are being sanitized with hospital grade disinfectant.  Debit and credit cards but NO CASH payments will be accepted.

COVID-19 symptoms are not always obvious.  We want to fend off this pandemic and minimize risk to our patients and the Foresight staff as front line health workers.   Contact that is closer than 2 m (6 feet) is to be avoided, with barriers in place when this cannot be avoided. We choose to continue to do our work and cautiously take care of our patients with compassion, humility, gentleness, and patience.   It is a challenging and new experience for many of us, so let‘s support each other and prevent virus spread!  Beyond 2020, our focus is on take care of you and keeping Clean Hands, Clear Heads and Open Hearts.   For more information, please refer to the following web pages or phone Health Link 811.

www.albertahealthservices.ca

www.collegeofoptometrists.ab.ca

Drs. Dianna Leong, Anh Bui, Andrew Chan

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Please note our upcoming holiday schedule:

Starting tomorrow December 22nd will be closed through December 26th. Additionally, we will be closing early on New Year’s eve at 3:00 pm and we will reopen Saturday, January 2nd.

We wish you Happy Holidays and a Happy New Year.