Need help re: correct method for measuring fitting heights PAL

[optin]

I am trying to prepare a training on Selling, fitting, dispensing and troubleshooting progressive lenses. I have found that many Opticians have a different method for measuring the PAL height. See bleow for some of the examples:

Brooks and Boorish, 3rd ed, pg. 455 ...eye level. With wearer looking at the bridge of the fitters nose, fitter draws line through center of pupil. (Paraphrase)

Darly Meister, Progressive Lens Dispensing Module 10, Eye level dot pupil center on demo (paraphrasing)

2020 Optician Handbook -... ask the patient to put on the glasses so they place them where they are comfortable wearing them. Then, with your eyes at the same height as the patients dot the fitting height with a marking pen.

Varilux fitting guide Eye level and draw line through pupil center.

I have seen it suggested that fitter Oclude left eye of patient while fitter closes right eye draw line through pupil center of patients right eye and vice versus. i think I saw this one in an OD training article.

I have witnesed optician telling patient to look in the distance over the fitters shoulder.

There is concensus on all other methods i.e. adjust frame first, correct vertex, panto and face form.

Unfortunatley we don't all agree on where the patient is to look, whether to occlude one eye of patient.

Most of us adopt the; eye level with patient looking straight ahead at our eye. Their left to our right and vice versus. Dotting pupil center. I like the suggestion that the patient place the frame on their face where comfortable and I also like the idea of drawing a horizontal line after center marked and checking that patient see's through this line while standing up.

There are alot of experts on this site and I appreciate your your thoughts on the correct way to measure fitting heights

[braheem24]

You forgot the online version 2/3rd or 5mm up whichever is least.

[Slim]

first I make sure frame is tweaked to perfection before i dot.

I get my eyes level with theirs, resting elbow on desk and dot. once dotted I draw line vertical and horiz. then lean or roll back a few feet.

If i am happy I have them take them off and "just put em on" naturally and look for repeat ability. Found that some dont put them on even close to "putting them on where they are comfortable"

[cocoisland58]

I think every optician develops their own "tried and true" method and if it works...it works. I pre-adjust, ask the patient to put the frame on and sit naturally. Then use my PD stick. I have never dotted the lens. Not saying this method should be the one used above all others but it has always worked for me.

[Happylady]

I use a penlight and mark the corneal reflex.

[DanLiv]

All those tips about having the pt stare in the distance or occluding an eye are to eliminate convergence for purposes of obtaining an accurate DPD. All the actual seg height information regarding bisecting or dotting the pupil to obtain the vertical measurement are in agreement. As long as the pt isn't tilting forward or backward but is level, convergence ought not influence your seg measurement.

[Roy R. Ferguson]

Out of curiosity, under what circumstances are progressive lenses not fit mid-pupil? This is not a trick question.

[Barry Santini]

Out of curiosity, under what circumstances are progressive lenses not fit mid-pupil? This is not a trick question.

Roy has a point: The client's pupil is *always* used in determining the initial reference height. Then, personal experience with lens design, patient posture and Rx delta are entered into the mix to determine fabrication height.

B

[optin]

Thanks to everyone for sharing there methods. I think we all agree that center pupil is the goal we just have different ways of getting there. I have one more question. How do you instruct patient to use PAL. Point there nose at what they wish to view and if near or intermediate point nose and adjust slightly if needed or .....

[Robert Martellaro]

I have witnesed optician telling patient to look in the distance over the fitters shoulder.

Important points of reference are TV watching and driving. I've had to go out to their vehicle on occasion. I always check the standing posture. Their posture must be relaxed and typical. It may take many tries before you get a realistic posture. Your eyes must be at the same level as the client's eyes. Have a stable chair or step ladder handy to stand on as needed.

I like the suggestion that the patient place the frame on their face where comfortable

I would recommend that it be placed where it is stable. Comfort is also important.

I also like the idea of drawing a horizontal line after center marked and checking that patient see's through this line while standing up.

Me too. I can see the occlusion of the corneal reflection better that way when I'm looking from off-axis.

Out of curiosity, under what circumstances are progressive lenses not fit mid-pupil? This is not a trick question.

Tall people, truck drivers, etc.

[DanLiv]

Roy has a point: The client's pupil is *always* used in determining the initial reference height. Then, personal experience with lens design, patient posture and Rx delta are entered into the mix to determine fabrication height.

+1, always measure at the pupil. However, fit at the height your design experience deems best.

[agr8194]

I always have the patient stand, I get a more natural head position this way. I pre adjust the frame, have them put it on and then ask them to stand and fix on a point eye level across the room. I then move in front of them to intersect their gaze, my eyes at the level of theirs. I close my right eye and ask them to look at my left eye, I then mark lower pupil edge of their right eye and vice versa for the patient's left eye. I then; without changing my position, instruct them to turn their head and look at the wall 90 degrees away and turn back to look at the bridge of my nose. If they make a vertical head adjustment to fixate on my nose I remark, starting over again. This method has worked quite flawlessly for me. Marking the lower edge makes the mark a little easier to see, and adding 1mm to that height gets me back into the pupil.