Choosing the Right
By Paul Engstrom, Aviation Writer and IFA Member
Few other personal items advertise 'the right stuff'
(be it real or imagined) as loudly as aviator sunglasses do.
Remember actor Tom Cruise and his fellow ace fighter
pilots in 'Top Gun'? They even wore sunglasses in the bar.
In the off-screen,
practical world of flying, however, cool-looking but inappropriate
shades can definitely mean the wrong stuff from a safety standpoint.
The price you pay for fashionable design could be a loss of visual
acuity, distorted color and images, even blind spots'those places in
your field of vision where other aircraft may be lurking, undetected.
That said, sunglasses do offer certain advantages.
They can reduce eye fatigue and harmful glare, and can make it easier
for your eyes to adapt to low-light conditions toward evening and
They can also block out
potentially damaging ultraviolet light, the intensity of which
increases 4 percent for every 1,000 feet of altitude. Too much of a
certain wavelength of UV light over time may cause cataracts, or
The goal, then, is to buy sunglasses tailored to
your particular safety and health needs as an aviator. If they look
good, too, so much the better!
For example, because older pilots have less pupil
dilation than younger pilots do, and therefore need more sunlight to
see well, they should wear shades that block out less light, according
to Frank E. Dully Jr., MD, an aviation safety expert formerly at the
University of Southern California in Los Angeles.
On the other hand, about one-fifth of the population
reacts adversely to glare. So the pilots among them might consider
sunglasses that keep out more, rather than less, light. (Lenses with a
#1 rating block out 20 percent of incoming light, a #2 lens 70
percent, a #3 lens 85 percent and a #4 lens 95 percent.)
But all pilots should avoid polarized sunglasses,
says Dr. William Monaco, an aviation optometrist in Wilmington,
Delaware, because they eliminate the all-important glare or glint of
light reflected from other maneuvering aircraft that catches your eye,
alerting you to traffic nearby.
Other styles to avoid, according to experts,
- Lenses that get darker when
exposed to more light. They may not darken properly in the cockpit
if adequate light can't penetrate the window.
- Cheap, department-store
sunglasses made of soft plastic. They may not block out any of the
harmful UV light.
- Wrap-around glasses, which
impede peripheral vision.
- Yellow lenses, which make it
difficult to distinguish between red and green'important colors on
sectional charts and approach plates, for example, and at airports.
However, yellow may be helpful in blocking out the blue light in
smog, fog, haze and smoke.
- Mirrored lenses. Aside from
scratching easily, they can cause image distortions and blind spots.
- Generally speaking, your best
bet is #2 sunglasses with a soft green or gray tint that are
lightweight and have adjustable nose pads so the frames can be moved
close to your face for maximum eye protection.
When he isn't flying, Paul Engstrom writes and
edits from Sebastopol, Calif.
The information contained herein is meant for
informational purposes only. Neither IFA, nor Paul Engstrom assume any
responsibility or liability for events that occur due to actions you
or others on your behalf take based on the information given in this
article. You are proceeding at your own risk. It is strongly advised
that you seek the opinion and advice of a qualified aviation medical
examiner and appropriate medical physician for any medical needs you