Studies suggest that aging eyes could play role in a number of diseases
A recent story in the New York Times reports on new information suggesting that many problems we face as we age, including memory loss, insomnia, depression - even cancer - could be_ _caused by changes in our eyes. Many of us become aware of vision changes in our early to mid-40s, when we find, as my mother used to say, that "the print in the newspaper keeps getting smaller." What's happening, of course, is presbyopia. As the eye ages, the lens of the eye gradually loses its ability to focus on close objects, thus the prevalence of reading glasses in our mid-years. What we may not realize is that during our eye exams, our doctors have been doing more than deciding on the prescription we need for our glasses or contacts. They've been looking for signs of health problems, as well. Signs of diabetes and cardiovascular disease can be seen during an eye exam, and recently studies in France and Australia have found that eye doctors can be trained to spot early signs of Alzheimer's disease.
However, the information in the_ Times_ article suggests that changes in our eyes as we age are even more important to our overall health, or its decline, than previously thought. During the aging process, the yellowing lens allows substantially less sunlight to get to key cells in the retina that regulate our circadian rhythm, which is the body's internal clock. Problems with our circadian rhythm are thought to contribute to disease.
Increasingly, studies are showing that blue light is an important part of the spectrum that is filtered out by the eye's aging lens. Dr. David Berson, whose lab at Brown University studies how the eye communicates with the brain. Berson's team discovered that cells in the inner retina, called retinal ganglion cells" also had photoreceptors and that these cells communicated"directly with the brain. These cells have been found to be especially responsive to the blue part of the light spectrum. It stands to reason that surgery to remove the clouded lens (cataract) and replace it with a clear, artificial lens, may help our overall health.
Eye checkups are an important tool to evaluate our health
As increased knowledge of the eye and its importance to our general health evolves, the importance of regular eye checkups should become a priority. Age increases the need for the exams, not only for vision problems, but as one way to detect problems in our general health. In the case of Alzheimer's disease particularly, the eye may reveal the first signs of a problem, thus enabling people to get help from specialists at an early stage. For diagnostic reasons as well as disease prevention, we need to get our eyes checked and follow through on any health issues discovered during the exam.