I'm an optical dispenser and I'm currently working in a lab fitting lenses, especially higher base curve lenses to really wrapped frames. We do a lot of compensation and prism decentration. Im really enjoying your videos would love to see more videos on prism and verting. I've found your videos really helpful! Thank you.
I have several videos on the list but until I can afford one or get someone to loan me a high end auto-lensmeter they aren't going to happen. I actually have the lenses here and the ideas ready to go but my own skill set with high prism and a manual lensmeter isn't good enough to produce a video that meets our standards. I need the double-check/proof if you will of confirming what I am seeing/doing. Was there a specific topic you were looking for? John
This will be interesting for me (learned consumer) Designing my 3D frames to induce decentered prism, using SV lens from my old broken frames (when I had no 🔼 prism)
- Good afternoon professor I want to ask you if you can show us how to do a manual Assembly of prismatic lenses (glasses) with all the steps from the prescription to the assembly in a video ? Thank you professor...
If I can ever get my hands on a good auto-lensmeter I sure will. It crosses over with another prism topic I'd like to cover but can't without one. Trying to convey what you want to see in the manual lensmeter is next to impossible and there is no way to capture it on video. At the same time I think that the video does a pretty good job with that? WYSIWYG so if you place the target to match the prism required, dot the lens, (DON't MOVE IT) and place the dot where the pupil is you should get what you need. John
Good morning professor, thank you for your answer I wish that you can have one, I am so happy your channel helps a lot of students, especially for mountain of glasses , practical and theorical courses, I didn't find any book to explain the steps of the assembly of glasses especially special lenses like prismatic one. thank you so much
Good Afternoon Sir Can you pls make a video on digital lensmeter, what tolerances are acceptable for spherical and cylindrical power and the Step Option in Lensmeter
Tolerance is covered in detail in the first two parts on Verification - Final Inspection. The third is going up this Thursday morning. With a digital lensmeter it is simply WYSIWYG what you see is what you get. If you know how to use a manual the auto will just take a few minutes to grasp. John
< First time diagnosed needing prism. I blame looking at mobile device up close during the 2020 pandemic, training my eyes to be cross-eyed. I wonder if the condition will reverse once "normal" life activities resume.
I have progressives. I saw that my PD:29.5/30.5 and my NPD:26.5/27.5 Is it possible they have such a near PD so as to give me some prism? I did try a prism on my progressives but I do not need it for distance, only near. When they ordered them with prism, it messed up my distance. If this is true, should a prism be mentioned on my prescription or the requirement to have a decrease in near pd on it? If it is not, how do I guarantee I get a pair of functioning glasses? I had to sneak these measurements since they would not give them to me and was able to have them show me the computer on another topic and saw them.
The difference between a distance and a near PD is from the eye's natural convergence where they rotate a little down and in to see things at near. As a rule you either need prism or you don't. Honestly it sounds like you need to find a doctor and/or an optician that you trust to make a pair of glasses. You are just throwing random darts at a board... John
your story about the sunglass restriction, sounds just about like the Oakley just had. Surprised about your insider 'trick' of shifting the PD, to get a 'prism effect'
Yeah - I figured you would pick up on that. Sorry but my original answer doesn't change. With prism and those powers in a heavy wrap - it ain't gonna work. But heck if you are going to do it anyway find someone who will use a wrap compensated free-form design (maybe an IOT) and let us know how it works out. I'm not sure how they will overcome the laws of physics but hey you never know.... John
I've been diagnosed with vertical heterophoria and am currently wearing glasses with a right lens that has 1.5 base up prism and a left lens that has 1.0 base down prism. It may not make a difference, but my farsightedness correction is +2.25 in each lens. I'm struggling to get used to these glasses because head movement and turns induce dizziness. Would this method of incorporating prism help to resolve the dizziness caused by head turns, assuming that the prism in the glasses is really the cause of the dizziness? I don't suppose the way light hits the lenses is an issue as it is with lenses that have actual prism ground in? Thanks for your help.
Sarah, No the result would still be the same if you could create enough using this method. Just a hunch but yeah I'd say the prism is probably the cause of the dizziness - but it had to be requested for some reason. Double vision can't be much better than dizziness? Sorry - but prescribed prism really is an art and science best handled by a doc with lot's of experience. John
Hi!If i understand corect you can't create prism by decentration if asoci7ated power sphere or cyl is unde +-1.So how do you create prism in a lens that has no power only the prism is required or i have like 0.50 cyl?
I'm an optical dispenser and I'm currently working in a lab fitting lenses, especially higher base curve lenses to really wrapped frames. We do a lot of compensation and prism decentration. Im really enjoying your videos would love to see more videos on prism and verting. I've found your videos really helpful! Thank you.
I have several videos on the list but until I can afford one or get someone to loan me a high end auto-lensmeter they aren't going to happen. I actually have the lenses here and the ideas ready to go but my own skill set with high prism and a manual lensmeter isn't good enough to produce a video that meets our standards. I need the double-check/proof if you will of confirming what I am seeing/doing. Was there a specific topic you were looking for? John
you are the best my teacher ❤️
This will be interesting for me (learned consumer) Designing my 3D frames to induce decentered prism, using SV lens from my old broken frames (when I had no 🔼 prism)
- Good afternoon professor I want to ask you if you can show us how to do a manual Assembly of prismatic lenses (glasses) with all the steps from the prescription to the assembly in a video ? Thank you professor...
If I can ever get my hands on a good auto-lensmeter I sure will. It crosses over with another prism topic I'd like to cover but can't without one. Trying to convey what you want to see in the manual lensmeter is next to impossible and there is no way to capture it on video. At the same time I think that the video does a pretty good job with that? WYSIWYG so if you place the target to match the prism required, dot the lens, (DON't MOVE IT) and place the dot where the pupil is you should get what you need. John
Good morning professor, thank you for your answer I wish that you can have one, I am so happy your channel helps a lot of students, especially for mountain of glasses , practical and theorical courses, I didn't find any book to explain the steps of the assembly of glasses especially special lenses like prismatic one. thank you so much
Good Afternoon Sir
Can you pls make a video on digital lensmeter, what tolerances are acceptable for spherical and cylindrical power and the Step Option in Lensmeter
Tolerance is covered in detail in the first two parts on Verification - Final Inspection. The third is going up this Thursday morning. With a digital lensmeter it is simply WYSIWYG what you see is what you get. If you know how to use a manual the auto will just take a few minutes to grasp. John
First, thanks Laramy.
< First time diagnosed needing prism. I blame looking at mobile device up close during the 2020 pandemic, training my eyes to be cross-eyed. I wonder if the condition will reverse once "normal" life activities resume.
One of the things I'm researching now is; can prism be applied to Aspheric lenses, or prism can only be on Spherical
I have progressives. I saw that my PD:29.5/30.5 and my NPD:26.5/27.5
Is it possible they have such a near PD so as to give me some prism? I did try a prism on my progressives but I do not need it for distance, only near. When they ordered them with prism, it messed up my distance.
If this is true, should a prism be mentioned on my prescription or the requirement to have a decrease in near pd on it? If it is not, how do I guarantee I get a pair of functioning glasses? I had to sneak these measurements since they would not give them to me and was able to have them show me the computer on another topic and saw them.
The difference between a distance and a near PD is from the eye's natural convergence where they rotate a little down and in to see things at near. As a rule you either need prism or you don't. Honestly it sounds like you need to find a doctor and/or an optician that you trust to make a pair of glasses. You are just throwing random darts at a board... John
your story about the sunglass restriction, sounds just about like the Oakley just had. Surprised about your insider 'trick' of shifting the PD, to get a 'prism effect'
Yeah - I figured you would pick up on that. Sorry but my original answer doesn't change. With prism and those powers in a heavy wrap - it ain't gonna work. But heck if you are going to do it anyway find someone who will use a wrap compensated free-form design (maybe an IOT) and let us know how it works out. I'm not sure how they will overcome the laws of physics but hey you never know.... John
Back again watching this video. I still want to get those wrap glasses 🤓
thanks a lot for your lessens.
i was just wandring,for the last exemple with the prism up, i think the eye will be down in the prism, i'm i wrong?
It was a minus lens. He moved it down so that it would create base up prism.
I've been diagnosed with vertical heterophoria and am currently wearing glasses with a right lens that has 1.5 base up prism and a left lens that has 1.0 base down prism. It may not make a difference, but my farsightedness correction is +2.25 in each lens. I'm struggling to get used to these glasses because head movement and turns induce dizziness. Would this method of incorporating prism help to resolve the dizziness caused by head turns, assuming that the prism in the glasses is really the cause of the dizziness? I don't suppose the way light hits the lenses is an issue as it is with lenses that have actual prism ground in? Thanks for your help.
Sarah, No the result would still be the same if you could create enough using this method. Just a hunch but yeah I'd say the prism is probably the cause of the dizziness - but it had to be requested for some reason. Double vision can't be much better than dizziness? Sorry - but prescribed prism really is an art and science best handled by a doc with lot's of experience. John
Hi!If i understand corect you can't create prism by decentration if asoci7ated power sphere or cyl is unde +-1.So how do you create prism in a lens that has no power only the prism is required or i have like 0.50 cyl?
It is surfaced in or the prism wedge is created when grinding the backside of the lens.
@@LaramyKOptical Thank you very much!I wish i had an optician like you in my town!Kind regards and big thanks!
I'd move the +7.50 lens 5.25D instead of 5; less margin of error.