Older Eyes Get New Lease on Life
WebMD News Archive
May 22, 2000 -- Find yourself getting farsighted as you get older? A new
operation that reverses age-induced loss of close-up vision may offer patients
a "fountain of youth for the eye," according to Gene W. Zdenek, MD.
Approximately 80% of people over age 40 require glasses or contact lenses to
read comfortably, says Zdenek, an ophthalmologist in private practice in
Reseda, Calif. At age 10, children can see small objects or print from two
inches away. By age 30, they have to hold the same objects six inches away, and
by 40 to 45, "we can no longer read comfortably at 12-16 inches,"
Zdenek says. It is around this time that most people start wearing glasses for
reading and other close-up tasks.
This loss of close-up vision with age is called presbyopia. For many years,
it was thought that presbyopia resulted from progressive hardening of the lens
of the eye. However, in 1994, Texas researcher Ronald Schachar, MD, PhD,
advanced the theory that the lens keeps growing throughout life, something like
an onion that keeps adding new layers. This leads to crowding of the eye
chamber and creates slack in the tiny, thread-like structures that connect the
lens to the muscles that make it change shape to accommodate the visual demands
we place on it.
Zdenek likens the process to pulling a wagon with a rope: "The wagon is
the lens, your arm is the muscle, and the rope is [the thread]," he tells
WebMD. "If there's too much slack in the rope, the wagon won't move when
you move your arm."
Presbyopia differs from true far-sightedness, in which the eye or cornea is
The new procedure. known as scleral expansion band (SEB) surgery, involves
placing four small plastic segments in the white of the eye, or sclera, to
expand the space between the lens and the muscles that control it. This
tightens the threads that connect the two, allowing the lens to once more
respond to the muscles that make it move, as it did when the eye was