Q: bifocal or progressive glasses?
Tim Hoel
it is getting harder for me to read maps. (At 48, presbyopia is setting
in.) I am now wondering whether it would be better to get bifocals or
progressive lens glasses for flying. Is there any common wisdom on this
subject, or for those who have gone before me, what is your opinion?
Thanks,
Tim Hoel
Logic Theorist
need) and having worked for an eyeglass lens manufacturer in the past here's
what I have learned.
Progressive lenses are not for pilots. In fact there have been several
accidents where progressive lenses were cited as a contributing factor. The
reason is that progressive lenses are not uniform from side to side. The
progression begins wide at the top and narrows at the bottom. If I were to
draw a diagram for you of the progressive area it would look somewhat T
shaped. What this does to the pilots peripheral vision is to distort it
considerably. All the accidents where progressives were cited as a
contributing factor involved landings.
Pilots who purchased progressives from the company I used to work for would
often complain to the customer service dept. of the problems they had with
them, specifically the distortion. The company's response was generally to
just give them a full refund or credit towards bifocals to be put in their
frames.
The latest from the FAA is that they are considering a ban on the use of
progressive lenses in the cockpit. The two largest manufacturers of
progressive lenses, Essilor (AKA Varilux) and Sola, are not putting up a
fight on this because they want to avoid the publicity and because they know
there are problems.
So what about bifocals? If you can still pass your class 1 try just using a
pair of reading glasses. Keep them around your neck with strap so they are
always there when you need to read something close up. Otherwise, if your
vision requires you to wear glasses full time and presbyopia is a problem,
bifocals may be the solution.
In my case, at 46, and having had to wear glasses most of my life I had
Lasik Surgery done and no longer need glasses. I too suffer from presbyopia
but I had my right eye made a little more near sighted than the left. For
now this has eliminated the need for reading glasses, but someday I will
probably have to use them. Lasik is not without it's pitfalls (e.g. poor
night vision) so if you consider this option, make sure you find a good
surgeon who knows his stuff.
One final note, all pilots who wear glasses (even sun glasses) should have
them coated with an anti-reflective coating. The difference is substantial
and worth the price. Also, photosensitive lenses such as Transitions do not
work in the cockpit and they reduce the contrast against a blue sky. Better
to stick with a good pair of sunglasses that you have purchased from an
optometrist that has guaranteed there UV filtering ability and has had them
AR coated for you. Even good off the shelf lenses provide only UV
protection, none come with an AR coating.
Hope this information helps,
Logic Theorist
"Tim Hoel" <t...@pclink.com> wrote in message
news:3a05cd1a$0$62630$7ba1...@news.pclink.com...
Stan Prevost
no difference in flying an airplane or driving a car in terms of peripheral
distortion or disorientation.
I have worn the progressives for about 10 years now, bifocals before that.
There are disadvantages to progressives, mainly for me that you have to turn
your head and point your nose at whatever you are looking at, whereas with
bifocals you can just use your peripheral vision or shift your eyes. But I
have adapted and have no desire nor perceived need to change.
Stan
Roger Halstead
N833R World's Oldest Debonair? s# CD-2
"Stan Prevost" <spre...@nospam.home.com> wrote in message
news:7PlN5.83250$P4.24...@news1.rdc1.tn.home.com...
> I wear Varilux progressives and have noted no problems VFR or in IMC. I
see
> no difference in flying an airplane or driving a car in terms of
peripheral
> distortion or disorientation.
>
> I have worn the progressives for about 10 years now, bifocals before that.
> There are disadvantages to progressives, mainly for me that you have to
turn
> your head and point your nose at whatever you are looking at, whereas with
> bifocals you can just use your peripheral vision or shift your eyes. But
I
> have adapted and have no desire nor perceived need to change.
To most of us, that periphial vision is essential to making safe, and good,
landings.
Roger (K8RI)
Roger Halstead
--
Roger Halstead (K8RI) www.RogerHalstead.com
N833R World's Oldest Debonair? s# CD-2
"Logic Theorist" <logict...@yahoo.com> wrote in message
news:ZhlN5.419$YQ5.2...@paloalto-snr1.gtei.net...
> Having been a pilot for over 20 years who wore glasses (Lasik ended the
> need) and having worked for an eyeglass lens manufacturer in the past
here's
> what I have learned.
>
> Progressive lenses are not for pilots. In fact there have been several
> accidents where progressive lenses were cited as a contributing factor.
<snip>
>
> One final note, all pilots who wear glasses (even sun glasses) should have
> them coated with an anti-reflective coating. The difference is substantial
> and worth the price. Also, photosensitive lenses such as Transitions do
not
> work in the cockpit
Transitions don't, but photograys do.
>and they reduce the contrast against a blue sky. Better
> to stick with a good pair of sunglasses that you have purchased from an
> optometrist that has guaranteed there UV filtering ability and has had
them
> AR coated for you. Even good off the shelf lenses provide only UV
> protection, none come with an AR coating.
All mine...Photogray, poloroid (which I prefer) and regular have the AR
coating.
Roger (K8RI)
>
> Hope this information helps,
> Logic Theorist
>
>
Stan Prevost
Roger Halstead <rdha...@tm.net> wrote in message
news:%wnN5.14786$mC.9...@monger.newsread.com...
> Roger Halstead (K8RI) www.RogerHalstead.com
> "Stan Prevost" <spre...@nospam.home.com> wrote in message
> > I wear Varilux progressives and have noted no problems VFR or in IMC. I
> see
> > no difference in flying an airplane or driving a car in terms of
> peripheral
> > distortion or disorientation.
> >
> > I have worn the progressives for about 10 years now, bifocals before
that.
> > There are disadvantages to progressives, mainly for me that you have to
> turn
> > your head and point your nose at whatever you are looking at, whereas
with
> > bifocals you can just use your peripheral vision or shift your eyes.
But
> I
> > have adapted and have no desire nor perceived need to change.
>
> To most of us, that periphial vision is essential to making safe, and
good,
> landings.
>
> Roger (K8RI)
>
Landings have never been my strong point. Perhaps that's a contributing
factor. How does one tell? Other than by getting a nonprogressive
prescription, spending enough time with them to become natural with them,
and see if landings improve?
Bob Koller x32611
After an initial period of adjustment, I was
able to wear progressives while driving and at work. I've worn the
progressives while flying with mixed results. Sometimes my landings go
well, others not (I'm still a student). It seems that progressives are
not quite as sharp as single prescription lenses, probably because the
image deteriorates due to multiple images produced. Flying at night with
them gives me a confused feeling. Anyway, the last few sessions I've
worn bifocals with much better results. So, my plan is to use bifocals
for flying and the progressives for other, not so critical uses.
bobk
Tony Simica
bifocals, is to have the bifocal (reading) lens moved down slightly so that
when you flare, you're not immediately looking out the lower lens. My flying
glasses were fitted like this. The eyeglass shop needs to know you want this
done or they will adjust the top of the bifocal lens as they do for
non-pilots.
Dennis Monroe
"Tim Hoel" <t...@pclink.com> wrote in message
news:3a05cd1a$0$62630$7ba1...@news.pclink.com...
diver.driver
the great eyesight I was privileged to have enjoyed before my 50th. I can
still pass a pilot medical eye chart test without glasses and have not had
to resort to memorizing the smallest line.
I obtained a full eye exam by a specialist ophthalmologist who did not sell
glasses. He confirmed that I was getting older and that both eyes were
healthy and equal. He told me to wear whatever I was comfortable with and
that he would give me a prescription for whatever strength I wanted so I
could get some better quality glasses paid for by my medical insurance.
Before 50 I always wore safety glasses and safety rated, polycarbonate,
tinted, mountaineering/aviator glasses. When I started experiencing
difficulty reading or in poor light I started wearing safety rated
polycarbonate readers. I keep several pairs and use different strengths
depending on how fine the work is. I found the best to be the spring temple
design as they are light, tough and harder to break in my shirt pocket. I
buy a package of two pair for 18 C$ at Costco. I started having trouble
reading aircraft instruments and found myself wearing 1 or 1.25 diopter most
of the time. These strengths also sharpen up my distance and night vision a
bit. For fine or detail work I keep a few pairs of 1.75 diopter glasses.
My biggest problem is that I have been unable to find any tinted readers. I
looked for clip ons but could only find very expensive ones and only to fit
modern Lennon sized but not large aviator type lenses. I have heard about
stick on bifocals for good quality dark glasses but have been unable to find
any for sale.
I would appreciate the groups help especially with a source for tinted
reading glasses.
Regarding Lasik, There is not a doctor on earth that I would trust with a
procedure so invasive. I would never take the chance that I would become a
failure statistic with something as important as my eyes. I have heard lots
of horror stories.
Others may have a greater need than I and "your mileage may vary."
"Logic Theorist" <logict...@yahoo.com> wrote in message
news:ZhlN5.419$YQ5.2...@paloalto-snr1.gtei.net...
> Having been a pilot for over 20 years who wore glasses (Lasik ended the
> need) and having worked for an eyeglass lens manufacturer in the past
here's
> what I have learned.
>
> Progressive lenses are not for pilots. In fact there have been several
> accidents where progressive lenses were cited as a contributing factor.
> One final note, all pilots who wear glasses (even sun glasses) should have
> them coated with an anti-reflective coating. The difference is substantial
> and worth the price. Also, photosensitive lenses such as Transitions do
not
> work in the cockpit and they reduce the contrast against a blue sky.
Better
> to stick with a good pair of sunglasses that you have purchased from an
> optometrist that has guaranteed there UV filtering ability and has had
them
> AR coated for you. Even good off the shelf lenses provide only UV
> protection, none come with an AR coating.
>
> Hope this information helps,
> Logic Theorist
>
>
johnp
i wear progressives (american optical omni-vision plus). it is true that the
peripheral part is 'unfocused'. it is also true that peripheral cues aid in
landing. but i don't think the peripheral cues need to be 'solidly in focus'
to help. at least, i like to delude myself that i can still grease 'em in
occassionally.
mho,
john
--
the end of the project is like the "whack-a-mole" game.
john.p...@amd.com
Roger Halstead
N833R World's Oldest Debonair? s# CD-2
"Tony Simica" <charles....@lmco.com> wrote in message
news:3A06EB44...@lmco.com...
> I have tried both and prefer the bifocal. One thing you might consider
with
> bifocals, is to have the bifocal (reading) lens moved down slightly so
that
> when you flare, you're not immediately looking out the lower lens. My
flying
> glasses were fitted like this. The eyeglass shop needs to know you want
this
> done or they will adjust the top of the bifocal lens as they do for
> non-pilots.
I had the line moved up, instead, but I have a relatively small aread for
close vision.
That lets me use periphial vision as if I were not wearing glasses.
Even with full stall, no flap landings where the only view is out the side
with periphial vision I have no problem.
The first time I brought the nose up to land (at night) while weating
progressives I saw two diverging runways. I yanked the glasses off and
threw them in the back seat. Then, I made a safe landing.
Roger (K8RI)
David C. MacLean
sunglasses at K-Mart, Wal-Mart, etc. They work well for me.
DCMacLean
In article <lYEN5.6466$pQ4....@jekyl.ab.tac.net>, nos...@3web.net says...
Bob Koller x32611
highflyer
>
> Although I was able to barely pass my first class medical without glasses,
> it is getting harder for me to read maps. (At 48, presbyopia is setting
> in.) I am now wondering whether it would be better to get bifocals or
> progressive lens glasses for flying. Is there any common wisdom on this
> subject, or for those who have gone before me, what is your opinion?
>
Tim,
As someone who has gone the whole route, from NO glasses for years to
encroaching problems with arms too short to read the charts I have a
recommendation.
If your distance vision is OK, you will probably get an initial
restriction that says you must have reading glasses WITH you when
flying. You don't have to wear them except to read the charts. If
you fall in that category, and I did for a decade, get a couple of
pairs of eight dollar reading glasses at Wal-Mart and throw them
in your flight bag.
If you also need correction for distance vision then you move into
"bifocal" country. I reached that point about ten years ago. I
tried bifocals. I carefully positioned the line so it would fall
at the top of the panel. It didn't work! The panel was too close
to see well through the upper distance vision part of the glasses
and it was too far away to see well through the lower "reading"
part of the glasses. I could land, and read charts, but I couldn't
see the instruments clearly.
Then I opted for "progressive" glasses. I had them start the reading
correction at the point where the top of the panel came. Then, as I
look down the focus point moves gradually from arms length to close
vision. Now I can see over the panel well, I can read the panel,
and I can look down in my lap and read the charts. They are great.
That being said, there IS a caveat! There is always a rub. It took
me about a year to learn to land with the darn glasses on. I fly a
large taildragger with a radial engine. I can't see a darn thing in
front of me once I start to flare. I normally glance down out the
corner of my eye at the edge of the runway to estimate my altitude
and alignment. When you look through the lower corner of the lenses
it distorts everything. The runway looked higher than it was and
at an angle to its alignment. I was consistently landing about
two feet above the runway and settling on rather firmly! :-) I
finally got my mind to crank out the distortion and got to where
I can go a decent three point landing again. But it took some
practice.
Now the progressives work well for me. Be aware that there IS a
significant period of adaption to the wildly varying focal lengths
and the peripheral distortions.
--
HighFlyer
Highflight Aviation Services
Thomas W. Pappano
I used various combinations of 3 different strengths of reading
glasses to get through my day and finally gave up and went straight to
progressives rather than trifocals. The first time I put them on I
about
lost my lunch because everything appeared extremely distorted; straight
lines in my lower field of vision appeared curved and the "sweet spot"
for
close up work seemed very tiny. The brain is truly amazing because
after
a day or two, the "curviness" went away and in a few weeks I could read
without constantly moving my head back and forth. I took up flying
after
I had been using these quite a while and I can find nothing to really
squawk them for. If I had overhead switches etc. it might be a problem
though. I'm a little farsighted so my correction is +.75 distant to
+2.75
close up. I like them fine but they sure were wierd at first! I think
one must be patient to give them a fair trial.
Tom Pappano, PP-ASEL and new IA student!