Common Causes of Vision Loss

We often take certain aspects of our health for granted, including our vision, when it’s one of the most important things in your life. Just like our other four basic senses (hearing, smell, taste and touch), our sight is equally crucial. The human senses are what connect us to the environment and society around us. Eyesight is critical because as much as 80% of what we perceive comes from our vision, and when our other senses stop working, such as hearing, it is our vision that best protects us from danger.

World Sight Day, which was first initiated back in 2000, is observed each year on the second Thursday in the month of October and is meant to raise awareness on the importance of eye care as well as draw attention to blindness and vision impairment. Globally, there are as many as 239 million individuals suffering with some form of visual impairment — with 246 million of those individuals having poor vision, and 39 million being blind.

There are many different causes of blindness, though the primary causes are often age-related eye diseases, such as cataracts, glaucoma, and macular degeneration.

Cataracts are the leading cause of vision loss in North America. They are classified as a clouding of the eye’s lens and can develop at any age — and can even be present at birth. In early stages, the symptoms of cataracts (such as blurred vision) can often be improved with eyeglasses. If your cataracts are in a more advanced stage, then you would require surgery to have them removed. Cataract surgery involves removing the clouded lens and replacing it with a clear, artificial lens. This is a relatively quick procedure that takes only 10 minutes (approximately) and is done on an outpatient basis, meaning you aren’t required to be hospitalized following the surgery.

Glaucoma, which occurs when the pressure inside the eye rises, can cause damage to the optic nerve and result in vision loss. There are two types of glaucoma that one can develop. Depending on the type of glaucoma that you’ve been diagnosed with, symptoms will either not be noticeable or be very noticeable (including eye pain and sudden visual disturbances.) If treated early enough, you can prevent major vision loss. If left untreated, the vision loss associated with glaucoma is irreversible. Treatment for glaucoma can include everything from eye drops to medication, and even laser surgery (or a combination.)

Age-related macular degeneration, also known as AMD, can result in blurred vision or blindness affecting the center of the visual field, and is the leading cause of vision loss in adults over the age of 50. Early symptoms and warning signs include the inability to see objects clearly, distorted vision, loss of color vision, or the appearance of a dark spot in the centre of your vision. If you notice any of these symptoms then you should book an appointment with your optometrist as soon as possible. While there is no cure for macular degeneration, researchers have discovered that including more eye-friendly nutrients in your diet (such as vitamin’s C, E and zinc) can reduce the risk of macular degeneration and other eye diseases.

For more information on World Sight Day, visit

Originally published at on October 6, 2018.



Dr. Ali Ghahary is a Family Physician in Vancouver, British Columbia, Canada.

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