double vision
I have a customer that purchased a pair of flat-top 28 when he looks straight above line in his distance RX he see's fine, but if he looks up not moving his head he gets a double vision. I have matched OC and base curves had him re-checked. I checked for waves in lens, what am I forgetting? Could this be a medical issue and not fixable with a RX. I had him take glasses off and without he gets a little but not as much as he does with the glasses. What am I missing, driving me nuts...
Difference in lens materials? What kind of Rx are we looking at? Differences in frame sizing and positioning?
Nothing in all the world is more dangerous than sincere ignorance and conscientious stupidity
What are his powers? Sounds like the is a significant power difference in his vertical meridian.
RX : OD 0.00-2.00x087
OS 0.00 -1.75 173 2.50 add could the axis, I put him in a cr-39 even match frame size he has been wearing.no AR he is not looking at top of frame.
and now, a refreshing interlude:
https://youtu.be/oxKCPjcvbys
The patient has a power imbalance, both vertically (1.75D) and horizontally (2D) every 5mm from the O.C. he'll have about 1D of prism imbalance. He should notice it moving his gaze horizontally too. Luckily, you've not mentioned double in his reading area. (If he did you'd need to consider a slab off design).
Tell the patient it's natural with this Rx and that he needs to turn his head more, pointing his nose in the specific direction he needs to look and not "scan" with eye movement much.
thank you so much, I will do just that. He had no double in near only upper distance when he looked at signs when driving and when he only used his eyes and didn't move his head. thanks again.
Just curious, what was his old Rx?
Caroline, L.O.
If you suffer from severe nonlinear waterfowl issues, you don't have your ducks in a row.
+1, he may also experience more visual freedom with a back surface digital FT 28.Originally Posted by optical24/7
I didn't attend the funeral, but I sent a nice letter saying I approved of it. Mark Twain
Right. In this case, the symptoms are related to the vertical prism imbalance, shortened to vertical imbalance, usually acronymized down to VI.
George, how often do we see WTR and ATR, at this level cylinder power, in one pair of eyes? It happens, but it deserves a red flag.
Does the frame have adjustable pads? Raising the distance optical center will decrease the vertical imbalance, if it's below the pupil center presently (likely). Make sure the subject is comfortable with the change in the segment height and the bottommost position of the lens on the downgaze before they leave your office.
You should probably get the prescriber involved if the problem continues, especially if it's been awhile since they were seen by their doctor.
Read the articles below. If you don't understand any of it let us know and someone will walk you through it.
https://www.2020mag.com/l-and-t/40051/ Ignore the references to Major Reference Point or MRP.
http://www.2020mag.com/l-and-t/44241/
Science is a way of trying not to fool yourself. - Richard P. Feynman
Experience is the hardest teacher. She gives the test before the lesson.
How about the OC height above the seg, is it the same for both sets.
I didn't attend the funeral, but I sent a nice letter saying I approved of it. Mark Twain
Yes, unusual to have WTR and ATR with the same patient. Most of the time it's post catx (turned out badly) or severe injury. The ironic thing is within hours of my post above I had a referring OMD send me a patient for an Rx check and troubleshoot with an extremely similar Rx as above. This patient wasn't happy about paying extra for a toric IOL and still having a pretty good amount of astigmatism (this surgery didn't go particularly well..)
He had been a long term PAL wearer. His post surgical purchase was made else where. Chief complaint was vertical diplopia in distance and near. The OMD office was puzzled because the glasses and Rx checked out. It didn't take rocket science to look at the Rx and know what the problem was. I asked if the double vision went away when he was looking through the intermediate (it did). These lenses had no prism thinning and the OC's were just under the PRP.
With his imbalance at 90, he was getting diplopia BD OD in dist. and BU OD at near. I've never been a fan of slab-offs on PAL's and recommended he get a segmented main pair w/slab-off and a separate sv intermediate for computer. The patient was happy knowing there was a solution as was the OMD. (Tough to imagine them not catching this one though, this was an easy-peasy troubleshoot.
How about a CL solution? Has he ever worn in the past?
They (torics IOLs) usually don't. I'm telling my mom to get a monofocal, non-astigmatic correcting, aspheric (if appropriate) IOL, when it's time.
How did that happen? Maybe on purpose, to better spit the VI between distance and near. Remember when we would order OCs aligned with the "top of the seg" when a slab was not desirable for some reason? Regardless, there must have been a high amount of VI, and/or their vertical fusional reserves were kaput.He had been a long term PAL wearer. His post surgical purchase was made else where. Chief complaint was vertical diplopia in distance and near. The OMD office was puzzled because the glasses and Rx checked out. It didn't take rocket science to look at the Rx and know what the problem was. I asked if the double vision went away when he was looking through the intermediate (it did). These lenses had no prism thinning and the OC's were just under the PRP.
We think alike. The best possible vision and comfort. Function before convenience, and function before fashion. That has to be, IMO, the starting point with all of our clients, especially for those with complex RXs (power, anisometropia, presbyopes, etc.) and/or those with compromised vision.With his imbalance at 90, he was getting diplopia BD OD in dist. and BU OD at near. I've never been a fan of slab-offs on PAL's and recommended he get a segmented main pair w/slab-off and a separate sv intermediate for computer. The patient was happy knowing there was a solution as was the OMD.
The surgeons aren't partially well trained for that. The over age forty ODs would pick it up, but might struggle with solutions. There's probably, and I'm being generous, about 500 opticians in the US who could analyze this correctly and then provide an optimal solution. Nice going.Tough to imagine them not catching this one though, this was an easy-peasy troubleshoot.
Science is a way of trying not to fool yourself. - Richard P. Feynman
Experience is the hardest teacher. She gives the test before the lesson.
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BTW- Robert made a great point a while back that a red flag should be raised any time the axes don't add up to close to 180.
Lots of worms to be found in that can if you're not careful!
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