Why and How Macular Degeneration Affects Vision
Age-Related Macular Degeneration (AMD) affects vision because the macula is part of the retina of the eye. The macula is located behind the lens on the back of the eyeball and helps images get to the optic nerve so they can be interpreted by the brain. The macula has the specific purpose of focusing fine details and enables people to read, drive, and see things like facial expressions.
So when the macula starts to break down and become dysfunctional, the central field of vision also suffers, though it leaves peripheral vision intact. This often causes confusion for those who are close to the person with macular degeneration because their eyes still look normal from the outside, so people don’t know why so much is missed by the one with AMD. At its worst form, what a person with AMD sees is almost like those scratcher cards that haven’t been scratched off yet — a blank circle covering the center area of where they look. Before that, the central vision may be distorted or partially “scratched.”
People with AMD are not blind, but they don’t have a full range of vision either. They are somewhere in between – as the former National Association for Visually Handicapped’s founding director, Dr. Lorraine Marchi, coined the phrase for AMD as being “hard of seeing.” A loved-one with AMD may not see the eyes of the person they are looking at, but they can usually see the general shape of the face. Since they know where the eyes are generally located, they can look at the eyes without seeing them.
In America, AMD — usually in the form of age-related macular degeneration— is the leading cause of vision loss for those who are over the age of 60. Studies show that exposure to UV rays, obesity, and smoking may increase the risk of AMD, and it seems to be more prevalent in Caucasians than in African-Americans. It has hereditary links and is also more common among women than men. Though there are two forms of AMD (wet and dry), 90% of those suffering from AMD have the dry, less severe form.
No cure has been found yet for AMD. With early detection, there are treatments that slow the progress of the disease, extending full vision longer. Have you been diagnosed with macular degeneration?
Dr. Travis Zigler
SOURCES: http://www.visionaware.org/info/your-eye-condition/age-related-macular-degeneration-amd/how-does-amd-affect-vision/125 http://www.vistaeyecare.net/your-eye-health/eye-diseases/macular-degeneration/