Optician Training: Prism Concepts Part 1

Prism Concepts 1: Is an introduction to the language, terms and general applications of prism.
Learn More: opticianworks.com/
For optician training or ABO NOCE study, this lesson covers:
Prism prescriptions and where they come from
Do these glasses have prism?
Verification of prism
How and why we use Prentice’s Formula
The patient - optician - practitioner triangle
Connect with us:
/ opticianworks
This video lesson is sponsored by Laramy-K Optical
Laramy-K Optical is a digital uncut and coating lab unlike any other. The only exclusively uncut lab in the country; we provide our customers with independent, high-end alternatives to corporate brands. Through craftsmanship, technology, and independent, innovative vendors like Younger, IOT, A&R, and Quantum Innovations we offer our customers the Integrity portfolio of freeform lenses and coatings. Made in the USA, the Integrity brand is not a generic house-brand, but is the absolute best available, designed to give the wearer that “wow!” experience.
In addition to the digital line, we still offer conventional surfacing, including glass. Maintaining traditional equipment gives our customers vastly more flexibility in their dispensing, particularly when it comes to more difficult prescriptions.
Learn More: www.laramyk.com

[@camiblutube7116]

Oh, I remember the Gong Show! And I loved it!

[@loribonalewicz5196]

Gene Gene the dancing machine!!! I am new to opticinary and have started Optician Works and want to thank you for being there for us newbies!!!

[@NateJamesAcoustic]

I remember the Gong Show, my parents did a great job. Thanks so much for putting these lessons out to KZbin. After 5-6 years pursuing different trades, I'm finally finding my way back to what I love and miss the most. These are proving the best refreshers around and I'm so glad to have found your videos and website. So informative and such a great reminder to all I learned when I was working on certification with Mark at the Dickinson Vision Center. I can't wait to get back to work

[@LaramyKOptical]

Nathan J DuBois seen confessions of a dangerous mind yet?

[@NateJamesAcoustic]

odd you should mention it, funny though that I haven't seen it yet

[@LaramyKOptical]

Try it, you will like it, great shtuffffff.

[@luisgomez1211]

Hello Laramy, here again, watching your interesting videos of Optical...prisms, I like this theme...thank you...

[@lynnettegarcia8125]

Prism and prism and Thank you. Understanding how something I do and work with daily and then translating it to a patient or student is challenging, thank you for creating these easy to understand videos.

[@Jessica-ft5ti]

I love all of your videos! I watch them before and after each chapter to understand what I read! Thank you so much!

[@LaramyKOptical]

That's the best way to do it. Twice the fun, twice the John too! ;-)

[@rakeshbali7209]

Wonderful..... If we deep concentratly go through then you learn to much.... Don't miss his interesting topics.... Big Salute.

[@marysonne1585]

I love that you created these video! 👍🏻 thank you much!

[@LaramyKOptical]

Thanks for watching, Mary!

[@tommyXraver]

the gong show was great!!

[@garyteves4077]

I loved The Gong Show, and I love to say words that start with "st" as "sht", just for fun. Maybe, I got that habit from watching The Gong Show, and didn't realize it?!

[@sarapringle7272]

Just what I needed!

[@LaramyKOptical]

Awesome! Thanks for the feedback.

[@ismai02l]

Thank you for sharing. Very easy and useful to refreshing the basics

[@LaramyKOptical]

Thanks Mohamed!

[@nassorabuu2110]

You are a Genius! I appreciate your work! God bless you.

[@LaramyKOptical]

LOL Genius, um, no. John is a bear of little brain... But thanks for the sweet comment. John ;-)

[@dsafghdgsf]

Thank you for good tutorial

[@nemesis851_]

Gong Show was fun, from what I remember of it

[@TKMcEachin]

Thanks so much for this!

[@flhtcui2000]

Smiling! I remember it, but I am 72 Gong Show, Chuck and Berry. One for you, Soupy Sales. Been having double vision issues the past year. Close ether eye and it's ok. Had RK done in 1990 and it worked good till about 5 years ago. Vision changes during the day now from + 200 reading glasses in the morning and few hours later prescription glasses. Not sure what my vision was before the RK but lets just say I couldn't see the big E on the chart. Went to my eye doctor today and looks like he going to put a prism of 1 out in both lenses to help with my vision. Hope it helps because I don't like closing one eye when driving pulling out in busy traffic. cylindrical +1.50 axis -2.25 prism 1 base out. cylindrical +3.25 axis -1.75 prism 1 base out.

[@LaramyKOptical]

Yeah - two eye driving whenever possible is better than one eye driving. We won't talk about 1981, alcohol & driving with one eye closed. I hope that 1 and 1 works out for you. John

[@loristec3275]

I watched the gong show in my youth!

[@LaramyKOptical]

Ever catch Confessions of a Dangerous Mind?

[@tonyamitchell6110]

Heck yeah I do!

[@snowfill999]

Superb

[@LaramyKOptical]

Thanks! I think that would be my first ever superb! ;-)

[@rakeshbali7209]

So many optician and opthalmologist ovoid the prism practice in refraction due to lack of pure knowledge. But , Sir make it simple practice of prism in refraction a wonderful achievment by optician and opththalmologist. If Sir you make it simple..... Thanks

[@setubosotubo]

@Laramy-K Optical Dear John ! Your videos have full details and the best technical level in whole Internet ! Congratulations ! As engineer I am watching all videos to learn a little bitte. Please 1- Is easy the definition of a Prisma in progressive lenses to solve diplopia ( in my case Rx: spherical myopia -7.75 both eyes, cylindrical astigmatism -1.00 both, Right Eye: at 160°, Left Eye at 10° , addition presbyopia +2.00 both eyes) ? or Is it really very difficult to have sucess at first time/lenses and also depends on the doctor to have years of experience ? I observed that my right eye has a devition and would be the root cause, to diplopia.

[@GinaChambers85022]

Thank you for this video & explaining the basics of prisms.. I am a patient of 50 and for years I have had difficulty with eye exams and have never been satisfied with my finished glasses & that they were the correct RX. Finally I found an optician who discovered that I needed 2 dioptres of prism for reading & 1 for distance. I asked if this type of muscular disorder was often found in neuromuscular diseases of the body or restricted to the eye & he responded yes it was common in MS, Fibro, etc and I should report the finding to my PCP. My question is what exactly is the disorder called when your optic muscles do not move synchronized to make vision optional? Warm Regards,Gina PS.~ I am aware this is is going above & deyond but is much appreciated!

[@LaramyKOptical]

Working on getting you the right answer. Might take a little time. John

[@LaramyKOptical]

Gina, I'll need an email address to send you what I got back on this. Just a couple of screen shots off popular optician FB page. John

[@nemesis851_]

In designing my 3D frames I’ve in last 2 years developed a prism 4 and i can design my frame bridge, etc exactly as I need. Just time, trial and error is where I’m at

[@bernicewest6874]

I do !🎉

[@setubosotubo]

To solve my diplopia (double vision), when I have 2 eyes open: I disassembled the lenses from the metal frame, and brought them closer together until I found the distance between the optical centers of the lenses, where I had good vision (no double vision). Simulating prismatic base out lenses in both eyes. In my case myopia, astigmatism and presbyopia. The lenses were mounted at a shorter distance (Pupile Distance), so as not to have double vision. 54mm instead of 68mm. And the lenses need to have a wider visual field width. It seems that having a correct prismatic lens prescription is difficult. And this practical method was faster.

[@LaramyKOptical]

Nice work! Clever. Glad that worked for you. John

[@setubosotubo]

​@@LaramyKOptical Thanks. I have another question, please

[@chadjohnson3736]

I know this video is about prism but is there anyway you could explain to me how to figure out what base curve to use when you only have the prescription and the Box system to go by and also the patient's PD

[@LaramyKOptical]

Chad, Base curve can be determined using Vogel's Rule, a base curve chart, or these days by letting the computer software decide or guide the best choice for a given Rx and material. I cover Vogel's and charts on the website. If you are neutralizing a pair of glasses (see this weeks video) then you should use a base curve clock and match the same one that is in the current pair of glasses. Remember that the lens clock is set for glass so if it is a surface job let the lab know what you got and how you got it so you don't end up with the wrong curve. Hope that helps! John

[@pauletteelizondo5441]

I remember the Gong Show

[@user-ic8gi2zv4z]

Hi Great video, one thing as a user of prism glasses that I have found is that no glasses dispenser seems to understand how thick a prism makes the lenses. I have a total of 11 Base in prism and the number of times I hear these are reading glasses we don't thin those. I always have to take on old pair of reading glasses with me when I order new readers to demonstrate just how thick the lenses are at the nose . So it would be great if you did a video showing the effect on the lens of adding Prism - Then I can just point people at your video

[@LaramyKOptical]

11D is quite a lot of prism. Any optician should know that would create thickness issues. If the optician doesn't know what prism is then how do they know if the job ws even done right? I'd find a better optical shop and stick with them.

[@christinewerbowski215]

I remember the gong show!

[@LaramyKOptical]

Have you seen the movie, Confessions of a Dangerous Mind?

[@christinewerbowski215]

Yes, it was a great movie...

[@patyounger8904]

I am a customer not a student. I developed diplopia about 4 yrs ago. My ophthalmologist prescribed a prism prescription. My new prism glasses worked perfectly. One yr ago, I had a minor change in refraction -4.75 to -4.25 in one eye. I have had three tries by the same optical dispensary in my Dr's office. I accepted the last glasses but they really do not work as well as my original lenses that I wear now (diplopia not well corrected). I am 79 and have no diplopia reading; bifocal works well. My prescription: -4.75, +2.75, Prism 8 out on Rt lens, 1 up on R (cyl -.50 Left, Axis 097 L) We went with flat frame on last try; Is this a difficult lens prescription? If I have cataract surgery, my surgeon can correct with lens distance vision thus eliminating one variable in the prescription would this make the prescription easier to do correctly. I believe I need a new optician with three failures. Is there a process I could use to help find more qualified optician ?

[@LaramyKOptical]

Just my opinion- I'm not a doctor. At 79 I would certainly give cataract surgery a try. You will eliminate a lot of power - hence a lot of what is giving you trouble. 8D prism is quite a lot. John

[@patyounger8904]

@@LaramyKOptical Thanks so much; really nice having such a quick answer; I'm thinking I could use a Fresnell lens post surgery while awaiting my prescription.

[@stevendonohoe2150]

Hi Laramy, is it possible for prism to correct diplopia in the peripheral vision?

[@LaramyKOptical]

Not 100% sure what you are asking but, yes, that is what prism is often used for. That is doctor stuff not optician stuff. John

[@stevendonohoe2150]

Thanks for your reply. I know prism's are used to treat diplopia but I haven't been able to find much information regarding peripheral double vision & my optomistrist wasn't able to correct my issue. I don't have double vision looking directly at an object, i'm only seeing double in my peripheral vision. I want to merge the two prepherial images into just one image. Appreciate your feedback & really enjoy your videos even though I'm not a student 😊

[@chadjohnson3736]

can anyone help answer a question for me? how do you determine the minimum blank size with just the following information A=38 ED=38 DBL=14 and the patient's PD measurements are 25/26

[@LaramyKOptical]

MBS is a two step process: First determine ED then use the formula: MBS = ED + 2X decentration + 2mm. A+DBL52/2 = 26 26-25=1 26-26=0 38 + 2 + 2 = 42 38 + 0 + 2= 40 Lots of this on the website since so many people struggle with it. Note: It is not a formula at all it is just a really good guide!

[@setubosotubo]

@Laramy-K Optical , Mr. Laramy-K. Please. Is it possible to set the correct prescription of a Prism, just with the total off-center distance (mm)? In my case I created a prism via optical center decentralization, the lenses were mounted at a distance smaller than my pupillary distance. 7mm each side towards the nose, totaling 14mm. Prentice would be: (-7.75 spherical myopia x 7mm)/10 = 5.425 Prism in each lens. Cylindrical Astigmatism -1.00 Presbyopia +2.00 To have the correct prism lens, would it be enough to add +5.4 Base Out ? I heard, that the correlation between Prisma Prentice would not be exactly 1:1, when prescribing a prism by normal methods. I'm a layman on the subject, just a person who wears glasses.

[@LaramyKOptical]

I just spent 20 minutes replying and then KZbin dropped me... grrrrrr. If cylinder is present then you would need to determine the power at 0-180 using the power in oblique meridian formula. Your D would probably change a little. The add or presbyopia correction shouldn't matter in this. I'm assuming these are single vision or a lined style bifocal? You can't move a progressive lens to create prism. Many things come to mind here: Prism is about the brain and perception so it is correct that there is no 1:1 correlation between power, position and what an individual will perceive. Which is why it is best done in front of a phoropter or with using trial lenses. Experimenting may end up being costly and time consuming - sorry. If you are trying to self troubleshoot and order glasses online then you could order them with the PD you figured out you NEED, not your actual PD. Again assuming these are single vision that would be an inexpensive way to find out if you have things sorted. I hope this helps a little. Not an easy thing to sort out.

[@setubosotubo]

​ @Laramy-K Optical Thanks John. My glasses has PROGRESSIVE LENSES (Hoyalux VXT Premium, 1.67), not listed in hoyavision site, only in Brazilian site. Due to decentration, if I see with 1 eye, I must rotate litte bitte my head (up to 5°), to have perfect vision ( aiming to the optical central vision area), in this 2nd glasses mounted with 54mm instead real Pupile Distance 68mm. With 59mm, my 1st glasses 3 years before, not necessary rotate my head. When I detected diplopia, the doctors did not indicate prisma lenses... I found my own solution and informed them, if I reduce the DP I do not have diplopia... Patient teaching the doctor... But if my diplopia increase, I think my method would not have effect and I will must to try a real Prisma lenses, however the doctors are not good (low knowledge) to define a correct Prisma lenses... and each error costs U$D 600 (lenses)

[@setubosotubo]

With 54mm Pupile Distance assembly instead 68mm real pupile distance, with these PROGRESSIVE LENSES glasses, my vision is perfect in all distances far and near.

[@setubosotubo]

@@LaramyKOptical Hello I watch the Laramy´s video "Powers In Oblique Meridians Formula" in FBook . My case Right Eye: -7.75 spherical, -1.00 cylinder, 160°. Total Prisma power @ 180° = -7,86. Thanks for the video.

[@LaramyKOptical]

@@setubosotubo Sorry but - if you are moving a progressive lens around and finding an area of perfect vision it is because either the lenses were made wrong or it is just some kind of weird luck. The optics of a progressive lens just simply DO NOT work that way. In fact the prism reference point on a progressive is about 8mm below where you are looking through the distance. Nothing you are doing or calculating is transferable to a progressive lens. Really sorry but it just isn't and I can't help you.

[@elizabethp824]

can anyone help me solve this? OD -3.00 OS -1.50 PD 62 mm The glasses, when complete, have a distance between centers of 64 mm. What is the amount and direction of the induced prism in the RIGHT lens?

[@LaramyKOptical]

It doesn't really work that way but 0.3D BI or negligible or probably not noticeable. That is just 1mm off in each eye and that left eye is pretty low power. The answer to a tolerance problem would be 0.3 BI R 0.15 BI L.

[@shanisimpson9233]

I remember.

[@SayedKhedr-lz7ph]

What's meaning DS in a prescription of brism?

[@LaramyKOptical]

Not related to prism as far as I know. DS would be Diopter Sphere which simply means sphere or a spherical power without cylinder.

[@krishanlal5680]

Is there video which explains how t calculate near vision from Addition and Far Vision ?

[@Musturdjuice]

How do I get your email? I've heard you tell us we can email you if we have questions. I have a rx that you wouldn't believe. And I have a question.

[@LaramyKOptical]

Through the OpticianWorks website.

[@dianabarter7963]

I know the gong show!

[@LaramyKOptical]

Have you seen Confessions of a Dangerous Mind?

[@schaferhundschmidt1798]

Yes, I remember the Gong Show quite well. I did some "schtick" comedy as the Unknown Comic in the Jr. High talent show. Bombed horribly. 👎