7 essential facts about your eyes

Your eyes are a window into your overall health. We take a look at how they work.

By

7 essential facts about your eyes
Photo courtesy of Geneviève Caron
1. The eye works like a camera. Light enters the eye through a clear outer dome known as the cornea. The iris, the coloured portion that surrounds the pupil, expands and contracts to let light in. Just behind the pupil is the lens, which focuses light rays on the retina. Like film inside a camera, the retina captures images, sending them via the optic nerve to the brain.

2. Everyone will experience some level of vision loss. Presbyopia, or reading vision loss, occurs in one's 40s or 50s, says Dr. Jeffrey J. Machat, MD, a Toronto-based ophthalmologist. If close-up objects begin to appear blurry and you have to hold them farther away to focus, consult a specialist about reading glasses.

3. Looking at a screen for extended periods doesn't damage your 
eyes. You're more likely to experience dry eyes if you spend a lot of time 
on your computer, but this is a matter of fatigue, not permanent damage, says Dr. Machat. "You're not blinking as often, so your eyes get more tired more quickly and things get blurry."

4. The average person blinks 10,800 times per day.

5. Red-eye in photos is caused by the flash illuminating the blood vessels of your retina.

6. Every 12 minutes, a Canadian begins to experience vision loss.

7. Eyesight dos and don'ts:
Do: Wear sunglasses year-round. Exposure to ultraviolet rays can lead to cataracts (a progressive condition that results in hazy, discoloured vision) and age-related macular degeneration, a disease which leads to a breakdown of tissue in the centre of the  retina. Look for glasses that offer 100-percent UVA and UVB protection, and opt for polarized lenses to reduce glare from snow and water.

Don't: Use anti-redness drops. The more often you use them, the less effective they become, due to a process called rebound vasodilation. Stick with artificial tears instead of medicated drops.

For more health facts, check out these 6 essential skin facts.
                                               
This story was originally titled "The Eyes" in the July 2014 issue.
           
Subscribe to Canadian Living today and never miss an issue!



All rights reserved. Transcontinental Media G.P. © 2014