Common Refractive Errors Of The Human Eye

[@philipnicholson3216]

I'm a doc and using your videos to help train office staff (techs, not opticians) - great job and thanks for the time and effort

[@LaramyKOptical]

Please be sure to check out the full program at OpticianWorks.com. Thanks John

[@samhotard2499]

Taking my exam this November, going back and reviewing the beginning videos right now. Thank you so much for taking the time to make these videos, I can't begin to explain how much they've cleared up difficult concepts for me!

[@LaramyKOptical]

You are welcome. John

[@strawberrysunhat]

omg i’m commenting just cause you were sad... this video was so helpful!!!

[@LaramyKOptical]

;-)

[@DVSB100]

Some people seem to be confused about the minus sign in front of the cylinder in the compound hyperopic astigmatism example. The first meridian has a power of +1.50 (the sphere), and the power of the other meridian is simply the sphere and cylinder added together, in this case +1.50 + (-0.50), which is +1.00. Therefore in this example both meridians have a positive power, and so are both hyperopic. The minus sign just tells you that the cylinder has to be subtracted from the sphere.

[@LaramyKOptical]

Couldn't have said it better myself! Those concepts are covered in detail on the OpticianWorks website. Funny, few things get under my skin but the folks that post that it is "wrong" or that there is a "mistake" really bother me. One thing to say, "please explain" which I would gladly do. Quite another to watch a video that has been viewed 10,000 times and has been up for over a year and say it is wrong... This is social media, trust me there is a line of people wrapped around the block just hoping that I do or say something wrong so they can pounce all over it. John

[@susanhihar629]

👍👍your videos helped me pass my optometry certifications. I have recommended them to others.

[@robinszoo]

I have been away from optical for sometime watching your videos have been extremely helpful in refreshing my brain thank you

[@LaramyKOptical]

Thanks

[@shaykamaryam2166]

It's the best explanation ever.. I wish I could watched it earlier...

[@viewfromnowhen]

Wonderful video! I'm studying psychology and this video was recommended as we study the visual system - loved how clearly everything was explained, and the final quiz was very helpful as well. Thank you for uploading this!

[@LaramyKOptical]

This one too, this one too: kzbin.info/www/bejne/mnq1qHSFi7pke9U

[@carlaaddison9868]

I also appreciated the quiz at the end! haha funny costume!

[@MAysar5]

Thank you so much for this simplified video! Good content. And the quiz was so helpful.

[@خالدفايز-س7ظ]

Great full work , thank you !!!

[@MommyLane04]

Great videos! I am so happy I found them.

[@shubhendusingh4328]

Sir,u r very good to make things easy.

[@funkybaba6509]

Very well explained. Thank you for your efforts.

[@manaseetelaang328]

That was incredibly useful and the game was really fun to play, thank youuu!

[@clarewheaton7139]

So helpful! Easy to follow and understand.

[@Pro0osh]

An absolute legend... I wish you explained how spectacles work for each... and also I would’ve loved it if you showed how the cornea is misshaped in astigmatism with a drawing... But nonetheless... great explanation !

[@LaramyKOptical]

That is another video on the same KZbin channel along with What Is Astigmatism.

[@Pro0osh]

@@LaramyKOptical Oh really? I should've looked it up before commenting... appreciate your response 👍🏻

[@xheriblloshmi7464]

You are veryyyyy helpful. Thank you for these amazing videos. I will recommend your KZbin channel to my classmates.

[@LaramyKOptical]

Thanks!

[@jimenamunozmerino6414]

excelent video

[@wendyyoung7246]

Super easy to understand now!

[@roxannemua9350]

great video how common are refractive errors ? Idk what type of hyperopia i have my prescription is +4.25 both eyes and +6.50 both eyes and my cylinder is -2.00 left eye and -2.50 right eye so which type do i have im guessing compound hyperopic astigmatism? I also have accomodative esotropia my eyes turn in the left one especially up close and i have double vision

[@LaramyKOptical]

Roxzs, I'll guess that you are not an opticianry student? Refractive errors are as common as people wearing glasses and of course contact lenses. I see 6 out of every 10 as a stat online. I'm going to guess you have a near pair and a distance pair? Yes, you have compound hyperopic astigmatism. Esotropia might be corrected with prism and that is separate from the rest of the lens power(s). John

[@cocobun444]

For the Compound Hyperopic Astigmatism example: I didn't understand why the Cylander power was not plus power? Can Anyone comment on this? FYI i'm a new optician student. I understand we need Plus power to bring the convergence back in to the retina. I didn't understand the use of minus cyl.? Thanks in advance

[@cocobun444]

The other meridian is still plus power?

[@LaramyKOptical]

Courtney, It will take time before it clicks. Watch the other related videos and work through the OpticianWorks program. Plus cylinder is another concept not really related to refractive errors. The sign of the cylinder could be either for any of the errors. It is when you do flat transposition and see the total power (with sign) for each of two principle meridians of the lens that you can tell or "see" why it works that way. Keep at it - the lightbulb will go on! John www.OpticianWorks.com

[@LAGMI20]

So i was wondering i when i watch tv or on working on a computer mine eyebrows hurt with glasses on and when without mine right eye hurts but when i am leaning more to the right and turn little with mine head the pain is not so much is this also a refrecrive erorr or somthing else

[@cunningham.s_law]

which lens is harder to design?

[@jolenestratton6676]

I really appreciate these videos! They are a great companion to my classes!

[@poncedeleonDDS]

awesome explanation !! made everything clear

[@LaramyKOptical]

Glad you liked it! Thanks for watching.

[@manikantamanish4095]

Thank you sir

[@prashantkuril.6698]

Please explain shape of glass like spherical - or + etc.

[@LaramyKOptical]

OpticianWorks.com

[@operator8014]

Was the value of Compound Hyperopic Astigmatism supposed to be -1.50 -0.50 x45? The +1.50 seems like it would represent Mixed Astigmatism.

[@LaramyKOptical]

No hyper = plus. Trust me all the examples in that video are 100% spot on. Watch it again and the companion piece where I put the lenses in front of the eye to correct for the various errors. It'll click! John

[@Hepta.Asteras]

I have compound myopic astigmatism; had been using toric contact lenses and all was well. Moved to another country, got a new Rx and now I can´t read up close with them on. Doctor says it is presbyopia...but without the lenses I still read and see pretty well up close. Why? The doctor does not explain....

[@LaramyKOptical]

If you have an accommodative loss of -1.00 or in other words you would need an add of +1.00 and the new lens powers are -1.00 diopter stronger then when you remove them you have basically given yourself a +1.00 add. Or as the saying goes less minus is more plus and more plus is less minus. It's an odd combination of things working together. Of course you also have the basic concept of minus powers = nearsightedness. So you would be naturally nearsighted or able to read things up close. I'm sorry they weren't willing to take a few minutes and explain it but it does make sense. This getting old thing is quite unpleasant... John

[@ekyshwaryasigirisetti3691]

awsome and expecting some more vedios

[@LaramyKOptical]

You did see the other 72 of them right?

[@tusharsingh8698]

Sir, in compound hyperopic astigmatism why one lens's power is in negative value, i.e. why minus sign is put before 0.50. As in hyperopic we use only + lenses why minus is used here?

[@LaramyKOptical]

All (prescriptions) lens powers are written in minus cylinder form for optical problems. Most people use minus cylinder form. Lenses are actually constructed in minus cylinder. If you do your flat transposition you will see that lens has plus power throughout. John

[@osafkhan4388]

Presbyopia a refractive error or age related thing?🤔🤔🤔

[@LaramyKOptical]

Osaf, sorry I missed this question. Both really. Did you watch the other video that covers just presbyopia? The changes in the lens (usually) occur with age (40's) and the changes in the lens do cause trouble with the process of refraction. But, it is just different enough from the others that I like to treat it just a little differently. John

[@muhammad.hameem]

What about conical cornea???

[@LaramyKOptical]

Not a "common" refractive error. Keratoconus is something different.

[@muhammad.hameem]

@@LaramyKOptical can you please explain.

[@lorimichelle320]

💡

[@victoriasedlacek7704]

I don;t get it. I need to know by the type of rx that is written. There is something left out. in this. The drawings do not help.

[@LaramyKOptical]

Victoria, There is nothing left out at all. First things first. First we learn the refractive errors then we learn the lens designs that we create to correct them. Those videos are being worked on now. In the meantime if you want both just head over to www.OpticianWorks.com where I have lenses placed in front of the refractive errors. John

[@Dil.7]

Compound hyperopic astigmatism rx is wrong. Sph and cyl should be both plus rx

[@prantorahman2135]

Sir i am 16 years old...and i am struggling one eye blurness 6 months...my left eye is ok but my right eye is 6'9 amd i am really wanted to fix it..i really Don't want to wear glass...plz sir solve my prblm...many times my eye become closer and its really disgusting..plz solve sir..love and huge respect from Bangladesh

[@seinfan9]

Sir that is a very tall right eye you have. Thank you.

[@koonjsundardas8387]

I have my exam tomorrow and this quick video helped alot👍

[@wonapalie]

This is so helpful! You're enthusiastic and clear, and the quiz at the end was super helpful. Thank you! Will you be making more? I'm gonna check out you're other videos too.

[@LaramyKOptical]

Astigmatism and axis is actually on the bench this very minute. That will be out in a week or so.

[@carlossolorzano361]

I feel like my life has been taken away, I can’t even complete assignments and I am still in college

[@indianmulti-fandom7870]

This video was really helpful! Thank you 😊 I originally just wanted to understand the difference between my previous and current prescription as my eyesight has worsened but thanks to you I now know I have compound myopic astigmatism.

[@sadeqajeena]

Doctor thank you so much for your efforts, but there is a small mistake in the minute 7:20, when you were talking about the ( Compound Hypermetropic Astigmatism) the correction I think should be plus for both axes. All the best

[@alexandramatthews5076]

You’re wrong don’t forget your optical cross.

[@sadeqajeena]

@@alexandramatthews5076 yes Dear I know if we made optical cross it would be right, not wrong at all, but as a theory with compound Astigmatism he should put both sides +, SORRY doctor @Laramy-K Optical I did not mean a real mistake but should have used + for both meridians

[@laurenduran2567]

Love the quiz at the end! More videos with questions in them would be great!

[@jessicamcallister3817]

Optician student here ✋🏾 and this is very helpful

[@meganbradshawdetter7586]

This video was amazing! I'm a market manager for an optical retail store and started my Optician Apprenciship a few minutes the ago. I've not found another resource that helped me VISUALIZE the things I talk about all day long until seeing this!! Thank you!

[@LE-gs9vc]

I've started watching your videos a few days ago. Very informative, interactive, and cute. You remind me a lot of Bill Nye the Science Guy except you're John Seegers Ready and Eager :)

[@LaramyKOptical]

Thanks!

[@ralailla1558]

Awesome explanation, loved everything from the beginning to the quiz. Thank you.

[@sheko2780]

It's the best explanation thanks too much

[@schaferhundschmidt1798]

So a simple hyperopic astigmatism becomes compound hyperopic astigmatism by the magic of transcription?

[@blahblahblah71111]

Thank you for making these. The training at my office is awful. These videos have been a great help

[@raghadahmad1544]

This was so difficult to understand, you made it so simple thank you

[@ummulvara6852]

Sir... One Q. Why there is 4 line only in front of eye!!! We make more than 4 lines na

[@Apratim98]

Is it true that a myopic eye(for e.g due to more corneal curvature) has a smaller least distance of distinct vision(D)? Because D is reached when lens reaches its max bulging capacity i.e when accommodation is max but since the eye is myopic so its has higher baseline converging power so it has to accommodate less than a normal eye for a object kept as the same dist., so more accomodation is left as object comes closer so better value of D?

[@LaramyKOptical]

I don't "see" any harm in thinking about it that way. But you could have a shallow cornea and a long eye and have the same results. Looks like you already have a pretty good grasp of it all.

[@otiebrown9999]

8:00 What an incredible number of defects the normal eye has. Why does this happen. How do you prevent +0.5 diopters of hyperopia from developing?

[@LaramyKOptical]

So many ways to look at it --- our eyes developed to a world of 200,000 years ago... probably didn't notice much until 700 years ago. At least we have lenses to correct for most of the problems. You can't prevent or correct or reverse aging. Maybe in another 700 years but not today. Although I hear that Laramy-K's Better Vision Tonic works wonders! Just $49.99 for a 12 oz. bottle Visa & MasterCard accepted. Act now buy one get one free. ;-) John

[@abdulazizahmed-i2r]

i am happy to join and get such interesting video

[@acacianorison]

Thank you very much John for these awesome videos. if i have +2.50 sphere and -3.50 cyl, axis 140. Can you please tell how much astigmatism I have. i know i have mixed astigmatism.

[@LaramyKOptical]

Not really sure how to answer that. I don't think it can really be measured or thought of that way. I guess you might say "3.50 diopters of astigmatism." You might say, "quite a bit." I think you would need K readings like they use for contact lenses to really assign it a value. But I might be wrong! John

[@acacianorison]

Thank you indeed i have keratoconus

[@dadsonanand5820]

Great video! Many thanks

[@mihretwolde869]

I have myopia both eyes -5.5

[@sakinamasud5392]

Nice 7 types welexplained

[@AshesE]

Thank you for your videos

[@timashaq5908]

thank you so much, my exam is in a week

[@sadiyahashim8179]

Very nice and useful class

[@donaldturner6402]

Confirmed cool cognition

[@chris1980c]

Well done thx :)

[@gaozongyang3876]

Thanks for the trivia part at the end! Was very helpful!

[@LaramyKOptical]

You are welcome.

[@LaramyKOptical]

Thanks for watching!

[@roxannemua9350]

I have Accomodative Estropia im Hyperopic +4.75 each eye +6.25 reading up close and -3.00 cylinder asgtimatism how unlucky am i :/// after 2 lasik enhancements i regressed and im still far sighted my eyes regressed

[@jovithaj3676]

Thank u so much sir

[@mky5845]

R: 0.25-3.00x176 L: 0.75-3.00x21 They have tried to fix my axis more than twice, and it's still not right. I want to cry.

[@LaramyKOptical]

"Fix" your axis? I'm not sure what that means? With that much power aligning it correctly shouldn't be very hard to do.

[@rowidaibrahim8284]

Perfect 🥀

[@iPsychoxMacz]

Starting training

[@mmiller195]

Really like this review of all the ABO topics and watch you regularly.

[@LaramyKOptical]

Thanks! John

[@moseskafwabulula7068]

Thank you

[@RehamAlshehri-k6c]

I LOVE THIS

[@rezaestiko5698]

thank you

[@NoneMechanic101]

Very Helpful

[@LaramyKOptical]

Glad to be of service. ;)

[@justbeautiful3083]

thank you

[@l.waltermenezes8156]

AWESOME!

[@samarfaisal7975]

Amaaazing

[@cl-optix]

why did the compound hyperopic astigmatism have a plus minus prescription?

[@LaramyKOptical]

kzbin.info/www/bejne/kF7JYZ5spZeKY9k

[@yaminireddy317]

Your videos are very helpful.. Thank you

[@LaramyKOptical]

Thanks! John

[@qabashaitham6850]

❤❤

[@surendradig2624]

There's a wrong sign before 1.50 in compound hyperopic astigmatism

[@LaramyKOptical]

It's correct. But thanks for taking the time to give some feedback. John

[@abdirahmansaalih4998]

@@LaramyKOptical First of all, thank you very much for the videos. I have similar concerns about the signs. The sign in front of the 1.5 in the compound hyperopic astigmatism makes sense to me, going off of your explanation of things thus far, but the sign in front of the 0.5 is a little confusing to me. Since all the light is passing the retina, doesn't it mean the cornea is both misshaped and shallow, needing two different powers both of which call for converging the light, hence 2 plus signs?

[@LaramyKOptical]

@@abdirahmansaalih4998 You are confusing power with cylinder sign. The middle number in the lens powers is the lens cylinder amount. That amount can be written in two different ways depending on where you choose to start writing the powers. It is about direction the lensmeter drum travels NOT about convex-concave or true plus or minus powers. You need to get lens design down and how "prescriptions" are written to understand it. John

[@iclassy948]

thankyou. nicely explained and liked the last part, testing. keep it up sir.

[@LaramyKOptical]

Thanks for watching!

[@RaquelHi]

Say where we want the light needs to hit “They don’t reach where we want to be” say where , please

[@LaramyKOptical]

Here: 2:08

[@michaelashcraft8569]

I have an associate's degree in optical science from 1988, never even tried to practice! Too complicated, so, I made 145, ooo per yr driving trucks till retirement, fun watching your vids though! Combat medicine in Navy was easier! Doc Mike USN

[@TheDejatube]

🦁🙋🏻‍♂️HEY FIVE FROM CALI JTPLEO AND MY 👤#7PTSDANXIETY DOUBLE VISION AND WITH FLOATING DIAGNOSIS WAS HYPEROPIA DIAGNOSES PRESBYOPIA AND POSTERIOR VITREOUS

[@loganhatch]

There is one dislike on all of your videos....I think you made one person upset and they took it out through the dislike button on your KZbin videos! lol I love your informative videos and believe they will definitely help me pass my ABO coming up in a couple of weeks!

[@bechirbouchogafa4487]

Mr Larry Thank you so much for you're teaching this a very important lesson for me to know how this astigamtisme and misshapen of the cornea or the eye ball and the rays fall short so we have to put a + number for correction or to the rays fall short so we have to put a - negative number for the lenses but the axes with like 27 ° I don't understand so may god bless and may god gives a better life and knowledge !

[@HavocVulture21]

Really good content. I think the strange intro takes away from it though. And some people would definitely click away before seeing how good it is.

[@rashifarsya]

Thank you Sir, you're so helpful

[@ThePicklefluff]

Thank you! There are a couple of us studying for the ABO at work and we talk about your material all the time.

[@ellesoundsmusic]

i loved the intro and outro to this video lol!! this was really helpful thank you!!!

[@rawanaljunaid3332]

That was very helpful.... I really liked the questions at the end❤

[@kimtuyenhotran706]

Thanks for your teaching ! It’ so conspicuous !

[@nanaabuela382]

Great video! Very helpful! Thank you

[@mohammadkh5968]

thanks alot it was so useful 😀

[@LaramyKOptical]

Glad we could help, Mohammad. Thanks for watching!

[@LaramyKOptical]

Thanks love hearing that! John

[@r7-niluhayusriantariputri35]

im not gonna make you sad sir, thank you for making this video

[@avijitsarker9191]

This was very helpful 😍 Thanku

[@alyssabarroga6518]

Thanks, this was really helpful!

[@aizamuring]

so easy to understand! Thanks!