Through advances in the understanding of how the eye works and technology that can help reverse age-related problems, you can have good vision for a lifetime.
With age, your eyes do need more light to see, colors become harder to distinguish (particularly shades of green and blue), it becomes more difficult to focus on objects close to you, and adjusting to glare and darkness is more challenging.
Mucous cells in the conjunctiva, the mucous membrane that covers the eye and the inside of the eyelids, can decrease with age. Tear production can also decrease. Together, these two changes mean you might have dryer eyes as you get older.
But none of those are necessarily essential to having healthy sight. Basic steps that counteract such changes include seeing an eye doctor regularly, making changes to help yourself see better, and taking good, overall care of yourself.
There is also evidence that some foods are particularly good for maintaining healthy eyes, particularly certain fruits and vegetables.
Why can vision loss occur as you age? Compare your eye to a video camera, says ophthalmologist David Zacks of the University of Michigan. Just as light enters a camera, it traverses four main structures in the eye.
When those structures in the eye change, vision can be reduced or become distorted. At the entry point is the cornea, the window through which all light enters the eye.
That light is then focused by the lens on the retina, which Zacks says is comparable to the film in the back of a camera. The retina converts the light to a neural signal, which the optic nerve carries to your brain, like a cable that connects the camera to a television screen, in this case the world around us.
For this anatomical camera to work properly, the cornea must remain smooth and intact (which depends on a tear film for protection), and the lens has to maintain its shape and remain clear to focus images properly. At the back end, the complex retina and the optic nerve are essentially one unit. Without disease, they don’t necessarily deteriorate with age. But age-related diseases of the retina and optic nerve are more common in older adults.
By middle age, the lens becomes less flexible and can’t thicken as it could when you were younger, a condition called presbyopia. This affects your ability to focus close up.
According to a review of vision loss in elderly Americans, about one in three has some form of vision-reducing disease by age 65. The most common are age-related macular degeneration (AMD), glaucoma, cataracts, and diabetic retinopathy. All can be treated if caught early, particularly glaucoma and cataracts.
Among retinal diseases, AMD is the leading cause of vision loss and blindness in adults over age 65. About 15 million Americans have AMD, but most don’t know it until they begin to lose vision, according to the American Society of Retina Specialists (ASRS)
“Learning about this disease and scheduling an examination with a retina specialist could help preserve vision for a lifetime,” the ASRS says.
AMD starts with deposits called drusen, which form under the retina and over time increase in size and number until they damage or kill light sensitive cells. Another form of AMD involves abnormal blood vessels behind the retina that start to grow under the macula. The end result is the same.
If you’re over 65, or have a family history of AMD, you should consider seeing a retinal specialist because the earliest signs of AMD can be detected. Women and those of European descent also are at higher risk.
“Everyone age 50 or older should visit an eye care professional for a comprehensive dilated eye exam,” says the National Eye Institute. “Many eye diseases have no early warning signs or symptoms, but a dilated exam can detect eye diseases in their early stages before vision loss occurs. Early detection and treatment can help you save your sight.”
July 30, 2015
Christopher Nystuen, MD, MBA