Our goal is to provide and expand your knowledge on common eye diseases and conditions. Find out more about your ocular health in our categories here and come back regularly to follow our eye care blog.
What is nearsightedness (myopia)?
Myopia, or more commonly, nearsightedness, is a vision condition that affects your ability to see objects further away from you. You can see objects that are close to you clearly, but those further away are blurry.
Nearsightedness has the tendency to run in the family and may develop at various points in life; onset can occur slowly or swiftly.
What causes nearsightedness?
Nearsightedness is commonly caused by less than ideally shaped eyes or cornea. Light entering the eye should focus on the retina, if the shape of your eyes or cornea leads the light entering the eyes to focus in front of the retina, instead of on it, the image produced will be blurry.
What are some of the symptoms?
Do you have difficulty seeing objects at a distance? Do you persistently squint to try to make out those blurry objects? Do you find it difficult to see while driving, and more so at night?
You may be affected by nearsightedness.
Common symptoms include:
Inability to see objects at a distance as the objects are blurry
Headaches induced by eye strain
Squinting eyes to clear see clearly and constant blinking
Difficulty seeing at night
How can near-sightedness be treated?
Nearsightedness can be diagnosed by a thorough eye exam from a professional optometrist. Your eye doctor may prescribe corrective lenses to improve your vision by helping your eyes focus light on your retina. Common corrective lenses are glasses or contact lenses.
Refractive surgery, such as LASIK, is also a treatment option that can be discussed with your doctor.
What is Blepharitis?
Blepharitis is a condition characterized by inflammation of the eyelids. It is commonly caused by bacterial infection and to a lesser extent by toxins, viral infections or allergies.
What are some of the symptoms?
Usually the peripheral area surrounding the eyelids show redness and there are scales and flakes at the base of eyelashes. Those suffering from Blepharitis may also feel irritation, burning and/or itching sensations around the outer eyelids.
How can Blepharitis be treated?
There is currently no known cure for Blepharitis, but the condition can be adequately treated and controlled with early detection.
Treatment centers around improved hygiene with regards to eyelids. Thorough cleaning, prescribed antibiotics, and the use of lubricants are all potential treatment options.
What is Dry Eye?
Dry Eye is a condition characterized by a lack of moisture on the surface of the eyes causing inflammation. The human body produces a layer of tears, supported by various glands, that lubricates and moistens the eye. The primary causes of dry eye are malfunctions or impediment of the glands to produce enough tears or oils to sufficiently lubricate the eyes.
Dry eyes may also develop as part of the aging process or as a side effect of medications, or a by-product of other conditions or exposure to environmental factors.
What are some of the symptoms?
Common symptoms include:
Itching, burning, stinging sensation in eyes, and/or general irritation
Sensitive to light
Feeling of a foreign body sensation in eye
How Can Dry Eye Be Treated?
To treat Dry Eye, tears need to be preserved or replaced to provide moisture to the eyes. Treatment options can include prescribed medications, gels, ointments and/or artificial tear. It may also include the use of physical accessories such as wearing eye protection, against the sun or wind, or the use of an in-home humidifier.
Diabetes And The Eye
Diabetes is a chronic disease that prevents the body from producing enough insulin and prevents the body from using this insulin. This causes the body to have increased sugar levels in the blood stream also known as elevated blood sugars.
In Canada, the number of people living with diabetes is approximately 3.3 million. This is more than breast cancer and AIDS patients combined. Type 2 diabetes, or non-insulin dependent diabetes is the most common form of diabetes accounting for over 90% of cases.
If the blood sugar levels are not under control, diabetes can affect the eyes and cause severe complications to vision. Uncontrolled blood sugar levels can cause vision fluctuations and changes in nearsightedness, farsightedness, and premature presbyopes. People may experience blurry vision, and occasional double vision and loss of their peripheral vision.
More commonly, uncontrolled blood sugar levels can cause retinal blood vessels to leak leading to hemorrhages or bleeding inside the eyes. Bleeding leads to scar tissues, and in turn leads to possible permanent changes in vision. This is called Diabetic retinopathy.
Uncontrolled diabetes can also accelerate cataract formation, glaucoma, and possible paralysis of the nerves that control the eye muscles. Early treatment and diagnosis is key to preventing these complications to the eyes.
Here in the office, Dr. Chow and associates examines patients with diabetes on a daily basis. In Ontario with a valid health card, anyone who have diabetes can be covered under OHIP for yearly eye examinations. Dr. Chow and associates also help patients who show early signs of possible diabetes by referring them to see their primary care physician for further testing and blood work. After every diabetic eye examination, Dr. Chow will send a report to your primary care physician and your endocrinologist in order for us to work as a team to control your diabetes.
For more information, please see www.opto.ca/diabetes, diabetes association, etc.
What is Diabetic Retinopathy?
Diabetic Retinopathy is a condition resulting from damage caused to the retina by the effects of diabetes. Patients with diabetes have high blood sugar levels that damage blood vessels, which include those in the eyes. More specifically, blood vessels that supplies the retina are damaged, which limits the amount of oxygen that it receives. The blood vessels may also be more prone to bleeding, and correspondingly leak into the retina.
Hypertension And The Eyes
Hypertension, also known as elevated or high blood pressure levels, is a long term systemic disease that can lead to severe health problems including heart disease and strokes. When your blood pressure is constantly high, the pressure can damage the blood vessel walls. In turn, the body tries to heal itself by compensating and remodeling the blood vessels. This however affects the intensity and the way the heart pumps the blood to the body, leading to heart problems and possible strokes.
As the eye is the only structure in the body where we can actually look inside and see the blood flow, occasionally, optometrists can identify early blood vessel structural changes. For people who already have high blood pressure, if it is not under control, the pressure inside the retinal blood vessels can leak causing hemorrhages or bleeding inside the eyes. This is called Hypertensive retinopathy.
With severe hypertension, also known as malignant hypertension, the heart can release plaques or emboli that can travel to the eyes and block the retinal blood vessels causing retinal vein occlusions, also known as a stroke inside the eyes.
Since almost everyone as they get older will eventually develop hypertension, it is very important to have annual eye examinations, especially if you are diagnosed with it. Together along with your primary care physician, Dr. Chow and associates can help manage and monitor your blood pressure levels and help ensure a healthy eye.
For more information, please visit www.hypertension.ca
Pregnancy And The Eyes
Did you know that pregnancy can cause changes to your vision and your eyes? As we know, during pregnancy, there are vast body changes including hormonal changes, metabolic, changes, changes in fluid retention, and changes in your blood circulation, all which can affect your eyes.
Do you experience blurry vision? vision fluctuations? dry eyes? Puffy or eyelid swelling?
Vision Fluctuations & Blurry Vision
During pregnancy, women may experience vision fluctuations and blurry vision. These changes are usually a side effect of hormonal changes and fluid retention causing your prescription to change. The fluid may affect the shape and thickness of your cornea which leads to prescription changes. However this is usually a minor symptom and will resolve once you have your baby. During this time however, LASIK refractive procedures are not recommended as your prescription fluctuates.
Dry Eyes With Pregnancy
Dry eye is a common side effect from hormonal fluctuations during pregnancy affecting the tear production. This often results in symptoms of sandy gritty feeling, irritation, redness and itchiness to the eyes. Expecting mothers usually develop these minor symptoms during their first trimester and likely will resolve once you have the baby.
During this time, we advise patients to reduce contact lenses wear, avoid heavy- make up around the eyes, reduce computer screen time and take frequent breaks (see computer vision syndrome section).
Gestational Diabetes, Glaucoma, Lasik Options
Here at Dr. Chow vision care, we can monitor your ocular status during pregnancy. As a side note, once you have your baby, we recommend for the infant to have their first eye examination with us between the ages of 6 – 9 months of age. Please visit our “Frequency of Eye Examination” page for more details.
Cataracts are an eye disorder that typically occurs gradually with aging due to clouding of the lens inside the eye. When there is clouding, the image that is seen from the retina is not as clear which can result in mild, moderate or severe blurred vision.
When cataracts progress you can expect to notice the following symptoms:
Blurred vision which cannot be corrected with a change in prescription from your glasses.
Ghost images / double vision in one or both eyes.
Faded or less vibrant colors
Glare from sunlight, artificial light (for example night time driving and looking at
Even though cataracts typically become bothersome after the age of 55, some people can have congenital cataracts from birth or traumatic cataracts can form at any age with injury of the eye. Cataracts can also form from the long term use of medications including steroids, UV light exposure from sunlight, age- related, and cigarette use.
When a cataract prevents you from being able to do your everyday activities or causes
extremely blurry vision, cataract surgery is an option and is a simple out-patient
procedure. Ask your optometrist about it today.
Amblyopia (Lazy Eye)
Amblyopia is also known as “lazy eye”. It is a condition in which vision in one eye or both eyes cannot be corrected to 20/20 even after the correct glasses are worn. This is due to an abnormal development of vision during infancy or childhood. Approximately 3% of children and young adults have amblyopia.
In order to see 20/20 vision properly, the brain receives information from both the right and the left eye and combines the two images to see one clear picture of the world. When we combine the images, this is called “Fusion”. If the brain cannot fuse the images together, then it will learn to ignore or suppress the information from the eye seeing a blurry image, ultimately leading to deterioration of vision in that eye.
There are three most common types of Amblyopia:
Strabismic Amblyopia is usually caused by a crossed eye or one eye turning inwards, outwards, upwards, or downwards on straight gaze. The turned eye is not used by the brain since it is misaligned and this leads to deterioration or lack of vision development in that eye.
There are two types of Refractive Amblyopia
Refractive Amblyopia can be due to a difference in prescription between the two eyes. This can occur when there is a significantly higher prescription in one eye than the other leading to the brain preferring to use one eye over the other.
Refractive amblyopia can be due to high degree of prescription in both eyes. If the child at a young age have a very high prescription and is not corrected by glasses, the brain will slow down vision development in both eyes causing poor vision.
Strabismis is also known as any misalignment of the eyes due to an eye muscle condition. This can result in double vision or suppression of the image from the affected eye. It is estimated that 5% of all children develop some degree of strabismus and that most of these children first show signs between birth and age 21 months. Children does not outgrow strabismus and thus a prompt visit to the optometrist can help correct the misalignment either by glasses correction, vision therapy, prisms, or in some cases a referral can be made to a pediatric ophthalmologist for surgical options.
Strabismic Amblyopia is usually caused by a crossed eye or one eye turning inwards, outwards, upwards, or downwards on straight gaze. The turned eye is not used by the brain since it is misaligned and this leads to deterioration or lack of vision development in that eye
Age Macular Degeneration
Age macular degeneration affects about 1/3 of people 55-74 years of age and almost 40% over the age of 75 presents with some form of AMD. The macula is affected is the central, most vital area of the retina responsible for central, sharp vision and color.
Risk factors for macular degeneration include age (especially over 50), family history, high blood pressure, obesity, excessive light exposure and even smoking. Having a lighter eye colour also entails a higher risk. As an optometrist, we screen every adult for this condition and educate each patient on preventative measures to protect their eyes from macular degeneration.
Currently there has not been a cure for macular degeneration. Macular degeneration treatment options exist that can slow the progress of the disease or improve vision based on the type of macular degeneration being experienced. There are two main categories of ARMD.
Dry macular degeneration is the less severe form affecting 80% of people with AMD and may retain that way. Drusen are small white or yellow deposits which accumulate in the deepest layers of the retina and breaks down the normal functioning retina. As it builds up, there is further disruption at the retinal layers above and eventually it damages the photoreceptor layer responsible for images from a person’s central vision. Treatment actually begins with routine eye exams, especially after age 60. The goal here is to catch the development of ARMD early. If detected, you may be prescribed a specific mix of high-dose zinc and antioxidants that have shown an ability to slow the progression of the disease. There is also an Amsler grid that you can use at home that helps to regularly
monitor your central vision and alert for any changes.
Wet macular degeneration is more severe that can cause rapid, permanent central vision loss in just a few weeks. It occurs when bleeding begins in the deepest layers of the retina from leakage of new abnormal blood vessels that grow spontaneously. Early detection is critical for overall vision and treatment can include a number of options; including laser surgery, light-activated dyes that are injected into the circulatory system, or drugs injected directly into the eye that inhibit the growth of abnormal blood vessels that cause the wet form of the disease. At this stage, once vision is lost, it is rarely restored.
To understand further about the risks and the limitations of all macular degeneration
treatments, please discuss with your eye doctor.