By Robert N. Rossier, EAA 472091
This piece originally ran in Robert’s Stick and Rudder column in the May 2024 issue of EAA Sport Aviation magazine.
Those of us who have spent decades flying airplanes can count ourselves as lucky. But we might also recognize that nothing lasts forever — not our airplanes, and certainly not us.
Unfortunately for all of us, normal aging is a degenerative process. We simply can’t expect the same performance from our aging body parts that we enjoyed in our youth. Every visit to our aviation medical examiner for a flight physical might be met with some trepidation as we consider the challenges of aging that we all might face at some point. Such challenges might include heart conditions, high blood pressure, diabetes — not to mention the normal aches and pains that seem to come with years of wandering the planet.
But particularly troubling for pilots are changes to our vision, and those changes can be particularly pronounced when day fades to night. The trick is to be aware of the changes and take steps to identify and mitigate the performance gaps that can arise.
The Small Print
One of the first symptoms many of us face is difficulty with our close-up vision. We find ourselves struggling to read, particularly things like charts, approach plates, manuals, and even cockpit displays and instruments. These symptoms, common after the age of 40, are due to the lens inside the eye losing its elasticity, or ability to change shape — a condition known as presbyopia. With any luck, all we need is a pair of “cheaters” or reading glasses to help us focus on the fine print. Unfortunately, that isn’t the only change that commonly plagues our aging vision.
A Dim View
While we are more likely to recognize the need for help with our near vision, other visual changes aren’t as clear (pardon the pun). In recent years, I found I wasn’t quite so keen on night flight. For the most part, it was because I’m an early riser, and by the time the sun sets (particularly in summer), I want to be relaxing rather than flying. But I also have noticed that night flying, as well as driving a car at night, had become more challenging. But like the proverbial frog in a slowly heating pot, I really didn’t recognize the slowly evolving condition until a routine eye exam identified the development of cataracts.
Cataracts are a loss of transparency of the lens of the eye, which often occurs as people age. Symptoms of cataracts can include cloudy, blurry, or dim vision, diminished night vision, glare and sensitivity to light, the appearance of “halos” around lights, and the need for brighter illumination for reading and other activities. Some sources estimate that 18 percent of Americans over age 40 have cataracts in one or both eyes, while roughly half of those over 50 are affected by cataracts.
Fortunately, the condition can usually be corrected through cataract surgery to remove and replace the lens. The procedure is commonplace, quick, and generally painless. And the results can be astonishing. Following cataract surgery, I recognized the diminished capacity with which I had been suffering. Suddenly, the night environment was clearer and brighter, and that made a world of difference. In addition to improving my night vision, I ended up with 20/20 distant vision, which I had never before enjoyed.
In a real sense, our vision begins to fade into darkness as we age. Among the normal visual aging processes is a lesser ability to adapt to changing lighting environments. In an article on normal aging and the eyes, Dr. Gary Heiting, OD (Doctor of Optometry), states that, “As we age, muscles that control our pupil size and reaction to light lose some strength. This causes the pupil to become smaller and less responsive to changes in ambient lighting. Because of these changes, people in their 60s need three times more ambient light for comfortable reading than those in their 20s.”
According to the American Academy of Ophthalmology, older adults may also find that as they age, it takes longer for their eyes to adjust and focus in the dark. One reason may be that as we age, we lose the eye’s rods — receptors in the eye that allow us to see in low light conditions — sooner than we lose the cones, which provide our sharp, central vision.
The need for better illumination isn’t the only challenge typically encountered as our vision ages.
Another effect is what is called contrast sensitivity, which makes it more difficult to distinguish objects from backgrounds of similar color. This might make it more difficult to pick out traffic in hazy conditions or to detect water in a fuel sample.
As these various changes occur, we may find that flying — especially at night — can become a bit more challenging. But for some, even greater vision challenges can arise as we soar into our golden years, and routine exams are the prescription for identifying and treating these conditions.
Eye Disease
Some changes to our vision can be secondary to other medical conditions. For example, high blood sugar can result in a condition called diabetic retinopathy, which causes damage to the blood vessels in the retina.
This condition results in vision loss, and in fact is a leading cause of vision loss among adults. Routine physical exams can tell us how well we’re regulating our blood sugar, and proper nutrition and exercise can often play a role in maintaining good control.
Another debilitating eye condition is glaucoma. This family of diseases, often (but not always) associated with high pressure within the eye (intraocular pressure), causes damage to the optic nerve. If not identified and treated early, glaucoma can result in blindness. As with other gradual vision changes, this condition can easily go unnoticed.
If diagnosed, the condition can be treated through the use of eye drops that help lower the pressure in the eye, and by laser treatment or eye surgery to improve the drainage of fluid within the eye.
Macular degeneration, another common age-related eye ailment, is reported to be the leading cause of vision loss for those over age 50 in the United States. It is caused by protein deposits that collect beneath the retina, which can cause the macula — the center of the retina where vision is sharpest — to degrade. While there is no permanent treatment for macular degeneration, treatments are available that can slow the progression of the disease.
An Ounce of Prevention
Maintaining good vision is critical for those of us with a love for flying, and the best way to avoid problems is to get regular medical eye exams. More than simply checking our visual acuity, a medical eye exam typically includes a variety of tests to assess dryness, intraocular pressure, muscle function, and the condition of the retina and optic nerve. An eye doctor may also check for such issues as cataracts, glaucoma, corneal dystrophy, macular degeneration, and other ailments including gaps or blind spots in the visual field.
There is no way to stop the march of time, but if we properly manage the health of our eyes, we may find we can keep on flying — even at night — for a long time.
Robert N. Rossier, EAA 472091, has been flying for more than 40 years and has worked as a flight instructor, commercial pilot, chief pilot, and FAA flight check airman.