The eyes are a window to the inner health of your body, and a barometer of how healthy you are. For instance, conditions like hypertension or high blood cholesterol show up in the tiny capillaries in your eyes or in the discolouration of your cornea. Major eye disorders often occur in combination with systemic health problems like type 2 diabetes, heart disease or kidney disease. The most common reasons for vision loss, particularly in aging persons, include macular degeneration, glaucoma, and cataracts.
Macular degeneration. The macula is a tiny two millimeter wide pit in the center of the retina. For such a small structure, it has the important job of translating light information into electrical nerve impluses. The cells in the macula are very vulnerable to oxidation because they are exposed to ultraviolet light. Any changes in blood flow due to poor nutrition, lack of exercise or weight gain gradual weakens the macula by increasing fluid pressure on it. Age-related macular degeneration, or AMD, is the most common cause of blindness in North Americans over the age of 50. If you’re over the age of 65, your risk of AMD is increased if you have frequent exposure to sunlight with protective eyewear, you smoke, have lighter coloured blue, green or hazel eyes or if you’re a postmenopausal woman. Macular degeneration develops very slowly and vision loss can be prevented if it’s caught earlier. Early signs of AMD include: straight objects appearing bent, blurry or dark sports appear in the center of your field of vision or a change in colour or size when you look at an object it one eye covered. Consult an ophthalmologist immediately if you notice any of these signs.
Glaucoma. There are several types of glaucoma and they all involve damage to the optic nerve from increased pressure within the eye. The most common form is called simple or chronic open-angle glaucoma, which represents 90 percent of all glaucoma diagnoses. In this condition, the drainage canals in the eye become blocked and fluid is unable to completely drain out. Open-angle glaucoma progresses very slowly and is called the “sneak thief of sight” because it’s rarely noticed before permanent loss of vision occurs. Persons with diabetes, hypertension, clogged arteries, smoking or excessive alcohol intake, or a history of anemia or shock are considered at high risk for glaucoma.
Cataracts. At birth, the lens of our eyes are clear but, with time, it naturally becomes cloudy making vision hazy. Cataracts manifest themselves through poor night vision, glare or sensitivity to light, blurred vision or the need for brighter light when reading. Some people with cataracts also experience double vision in one eye, fading of colors, or frequent changes in eyeglass prescriptions. In come rare cases, the need for corrective eyewear may cease as the cataract changes the way the lens of the eye refracts and bends light. In most cases, cataracts do not cause permanent damage to the eye despite the serious changes to eyesight. Protective sunglasses slow the progression of cataracts but they can only be treated with surgery.
Save your sight! Natural Ways to Prevent and Reverse Macular Degeneration. By Marc R. Rose and Micheal R. Rose. Warner books, 1998. Chapter 4, pages 55-60.
All about your eyes: A Practical Guide in Plain English from the Physicians at Duke University Eye Center. Edited by Sharon Fekrat and Jennifer S. Weizer. Duke University Press 2006. Chapter 8, pages 66-7.