PAL for a truck driver

[Uilleann]

...with a nice bit of wackado cyl thrown into the mix. Here's what I'm working with:

-1.50 -3.75 x 168
-1.00 -5.75 x 015

+2.00 Add.

He has worn PALs before, but as this was his first visit to us and those previous 8 year old lenses were about as transparent as wax paper with loads of delicious scratches. :)

We're using an E partner lab for this one, and looking for a new PAL with a focus on distance sharpness/VAs. Was initially thinking an Auto III in 1.60 (as opposed to say a Physio DRx).

Thoughts?

[ThatOneGuy]

Auto III 18 would be fantastic, unless he hates not being able to read his log book, in which case you can try shortening to 15. If he drives during the day, I'd strongly encourage a pair of drivewear in auto iii.

[Uilleann]

We're doing a polar Chem clip for him - better than any photochromic lens for him. His seg is 22, so the 18 should fit fine. Not sure why that length would make his near difficult. I'm thinking he'll be OK on that front. Was more thinking about the best dist optic, and know the X, S, Physio, and Comfort designs are all just a bit soft in the dist. Hence the thought towards the Auto III.

[drk]

Now I'm confused.

I am wearing an S design and an Auto III.

The "S" (which is just a souped up Physio, IMHO) is definitely better in the distance.

The Auto III is heavenly at intermediate and near, but the horizon is quite soft above the 180 and with big pupils night driving, it's really not very good.

[Uilleann]

Good info Doc - and thanks as always. Have you laid your eyes on your own pair of X design yet either?? Would be interested in a direct comparison there too...

[ThatOneGuy]

Your auto iii pair is out of adjustment drk.

reading “should be fine” is a product of either over plusing (bumping the add) or a rare person. Certainly people adapt to whatever you give them, but a shorter corridor makes more people happy.

the reason for the long corridor is his position in the truck. He looks down at the road. If the corridor is too short, it can inhibit the view of the road

[drk]

OneGuy: there's no way that a trucker is going to use the addition portion to look at the road. Think that one through.

Are you saying that Autograph series has a hard 180? I am certainly influenced by the fact that I'm high minus and wearing high index.

[ThatOneGuy]

Depending on the size and series of truck, the driver position is relatively near to the windshield, and when they look at the ground in front of them (in a short corridor), then they may see the add. Further more, a long corridor will have less peripheral distortion, making the road clearer. Certainly some trucks don’t have good visibility. Most do.

some drivers don’t look at near enough to care where the reading area is. Many do, though. So as with all lens fits, it’s a game of give and take.

auto iii has a significantly wide distance field of view. If your distance is narrow, they are probably positioned too high on your face (or too low). It can sometimes be caused by lenses that are rotated in the frame (or frame is rotated relative to your face), or (less so) POW is out of adjustment. Also make sure you are using monocular segs.

index of refraction shouldn’t really affect your field of view if you are testing it stationary (as opposed to while driving down the road or jogging). It arguably could affect acuity, but that only helps you not notice distortion.

[lensmanmd]

Too bad you are using a big E product. A 19mm Camber Steady, IMO, would be the best choice, followed closely by a Zeiss ID2. Both have excellent edge to edge clarity.

[Chris Ryser]

..with a nice bit of wackado cyl thrown into the mix. Here's what I'm working with:

-1.50 -3.75 x 168
-1.00 -5.75 x 015

+2.00 Add.

He has worn PALs before, but as this was his first visit to us and those previous 8 year old lenses ........................................

This guy is close to retirement at that age, and should not get bothered by a small reading area and all the distortion that goes with it in the distance sector.

[Uilleann]

Too bad you are using a big E product. A 19mm Camber Steady, IMO, would be the best choice, followed closely by a Zeiss ID2. Both have excellent edge to edge clarity.

Camber lenses would have been my first choice too. But insurance, and finish quality were also at play on this one - hence the need to use the partner lab. :)

[drk]

Depending on the size and series of truck, the driver position is relatively near to the windshield, and when they look at the ground in front of them (in a short corridor), then they may see the add. Further more, a long corridor will have less peripheral distortion, making the road clearer. Certainly some trucks don’t have good visibility. Most do.

That doesn't compute, to me. While truckers do sit high, I can't envision what you say. Maybe I need to get in a truck.

auto iii has a significantly wide distance field of view. If your distance is narrow, they are probably positioned too high on your face (or too low). It can sometimes be caused by lenses that are rotated in the frame (or frame is rotated relative to your face), or (less so) POW is out of adjustment. Also make sure you are using monocular segs.

Thanks for the suggestions.

index of refraction shouldn’t really affect your field of view if you are testing it stationary (as opposed to while driving down the road or jogging). It arguably could affect acuity, but that only helps you not notice distortion.

I think it would. Off-axis optics are worse in higher indices, in general. Can anyone give me a confirmation on that?

I don't think that your concept of reduced peripheral acuity helping "mask distortion" is a good one. But that's probably just a theory on your part, so, hey, it's worth a consideration.

[Tallboy]

I agree with an AUTO III in 1.60. I would use a 15 mm corridor not 18. My 2cents.

I never have issues with periphery in Autograph lenses, but I'm only just now feeling the effects of the presbyo monster in my own eyes so my experience isn't my own, only through dispensing.

[Robert Martellaro]

...with a nice bit of wackado cyl thrown into the mix. Here's what I'm working with:

-1.50 -3.75 x 168
-1.00 -5.75 x 015

+2.00 Add.

He has worn PALs before, but as this was his first visit to us and those previous 8 year old lenses were about as transparent as wax paper with loads of delicious scratches. :)

We're using an E partner lab for this one, and looking for a new PAL with a focus on distance sharpness/VAs. Was initially thinking an Auto III in 1.60 (as opposed to say a Physio DRx).

Thoughts?

You'll look like a miracle worker when you place a set of pristine surfaced lenses in front of his eyes.

BCVA left will influence the decision process.

Coated segmented multifocals are recommended. Cut the add for the instrument cluster as needed. Maybe a separate PAL for dress as required.

A hard PAL design is indicated for high astigmatism, and would be cost effective. Adaptation might be difficult if he's presently wearing a soft design and a +1.25 add.

Shamir and Zeiss say they can mechanically go up to 6 DC, but it's minus on minus, and right at the dioptric power limit- I doubt that the optics in the left lens will be better than a semi-finished design, like the Physio. FWIW, the Zeiss Individual 2N has slightly better distance vision than the Autograph.

Note the induced vertical imbalance at distance (.6 PD BU left if a 4mm drop) and near (about 2 PD).

Hope this helps,

Robert Martellaro

[drk]

You're not getting off that easily, Robert J. Wapner.

Judge our dispute...is the Autograph II/III design near zone-heavy and distance zone-light?

We will accept your verdict.

[Robert Martellaro]

Off-axis optics are worse in higher indices, in general. Can anyone give me a confirmation on that?

True, for most brains. Ms. Jones was wearing eyeglasses where the lenses were reversed- after complaining about her poor visual comfort, her optician told her everything was fine and went on to wear them another two years. As C. Berry said, you never can tell.

CR39 and crown glasses have the least chromatic aberration/off-axis blur, Trivex and 1.60 moderate values, 1.74, 1.67, and Poly the most.

Best regards,

Robert Martellaro

[Robert Martellaro]

You're not getting off that easily, Robert J. Wapner.

Judge our dispute...is the Autograph II/III design near zone-heavy and distance zone-light?

We will accept your verdict.

Good morning, judge.

Let's just say that the near zone is high and mighty!