Between the age of 40 and 50, a universal sign of aging, farsightedness, begins. Also known as Presbyopia, the medical term comes from the Greek word for ‘old man’, presbys, and opia-sight.
The lens can be thought of as having a “Gummy Bear” viscosity, allowing it to flatten when fibers holding it from around its circumference, like the springs around a trampoline, are pulled open . The trampoline springs are themselves connected to and controlled by a relaxed circular muscle sphincter. This focusing mechanism allows you to see objects from distances of 1.5 inches up to infinity.
At rest, the muscle that controls the trampoline (aka Gummy bear lens) is a big circle so that the lens is maximally flat and permits viewing of objects that are far away.
With Myopia (aka nearsightedness), you need glasses to see objects that are far away because the lens focuses the image before the back wall of an egg-shaped, myopic eye:
But keep in mind, the problem with nearsightedness is not the lens. It is as though you had moved a slide projection screen farther away after the focus had been established.
To focus on objects that are progressively nearer, like newspapers and prescriptions bottles, the circular muscle will constrict, thereby letting the ‘trampoline springs’ slacken, which in turn, permits the central Gummy Bear/lens to become rounder.
So you need reading glasses as you age because even with the circular ‘lens sphincter’ becoming its smallest circumference, the Gummy Bear has become too hard to take on its rounder, more light-refractive state.
And if you have an egg-shaped eye AND your lens has become a harder Gummy bear, you’ll have myopia and presbyopia and you’ll be needing need bifocals or two sets of glasses.
Reading glass strength is measured in diopters. Click here for a site to test your own eyes.
Although just anecdotal, one of our recent 1 year follow up patients, a gentleman 65 years of age, actually had his reading glass prescription weaken from 2.5 to 2.0 diopters. While taking TA-65, his lens must have become softer.
Even more surprising were the radical improvements in his myopia reflected in his farsighted vision. This might also be attributed to the softening of the lens, thereby allowing the maximally relaxed sphincter and its trampoline springs to pull the lens flatter.
In isolation, there may be a simple explanation. But over the next two posts, we’ll share his improvements in lung capacity and arterial stiffness, which are also universally-deteriorating signs of aging. Together, these improved biomarkers paint an picture of a man growing younger!