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

[@mondaymorningswithmel]

these videos have been ESSENTIAL for studying for my ABO. you make it so simple and entertaining. THANK YOU

[@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!

[@jolenestratton6676]

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

[@laurenduran2567]

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

[@strawberrysunhat]

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

[@LaramyKOptical]

;-)

[@jessicamcallister3817]

Optician student here ✋🏾 and this is very helpful

[@kimtuyenhotran706]

Thanks for your teaching ! It’ so conspicuous !

[@خالدفايز-س7ظ]

Great full work , thank you !!!

[@robinszoo]

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

[@LaramyKOptical]

Thanks

[@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

[@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.

[@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.

[@shaykamaryam2166]

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

[@blahblahblah71111]

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

[@ralailla1558]

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

[@ellesoundsmusic]

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

[@MAysar5]

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

[@koonjsundardas8387]

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

[@ThePicklefluff]

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

[@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

[@susanhihar629]

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

[@MommyLane04]

Great videos! I am so happy I found them.

[@aizamuring]

so easy to understand! Thanks!

[@clarewheaton7139]

So helpful! Easy to follow and understand.

[@wendyyoung7246]

Super easy to understand now!

[@myrumi5000]

It helped me a lot. Thanks

[@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 !

[@raghadahmad1544]

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

[@manaseetelaang328]

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

[@funkybaba6509]

Very well explained. Thank you for your efforts.

[@shubhendusingh4328]

Sir,u r very good to make things easy.

[@gaozongyang3876]

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

[@LaramyKOptical]

You are welcome.

[@LaramyKOptical]

Thanks for watching!

[@carlaaddison9868]

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

[@dadsonanand5820]

Great video! Many thanks

[@alyssabarroga6518]

Thanks, this was really helpful!

[@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.

[@nanaabuela382]

Great video! Very helpful! Thank you

[@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

[@xheriblloshmi7464]

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

[@LaramyKOptical]

Thanks!

[@NoneMechanic101]

Very Helpful

[@LaramyKOptical]

Glad to be of service. ;)

[@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

[@sadiyahashim8179]

Very nice and useful class

[@rawanaljunaid3332]

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

[@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

[@poncedeleonDDS]

awesome explanation !! made everything clear

[@LaramyKOptical]

Glad you liked it! Thanks for watching.

[@jimenamunozmerino6414]

excelent video

[@simarsohal3942]

Really helpful. Never found such a determined teacher 🙄

[@LaramyKOptical]

Well, determined is one word for it. I am called many things... ;-) John

[@yaminireddy317]

Your videos are very helpful.. Thank you

[@LaramyKOptical]

Thanks! John

[@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 👍🏻

[@cunningham.s_law]

which lens is harder to design?

[@iclassy948]

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

[@LaramyKOptical]

Thanks for watching!

[@mmiller195]

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

[@LaramyKOptical]

Thanks! John

[@Dil.7]

John, is the compound hyp ast rx displayed correctly? Should it not be a plus cyl according to your diagram?

[@LaramyKOptical]

No it is correct as shown. Do flat transposition and you have plus power in all meridians. No need for powers to be written in plus cylinder form. Cylinder sign has nothing to do with refractive error only the power(s). John

[@orioncoat5258]

It was helpful. Thanks a lot.

[@sheko2780]

It's the best explanation thanks too much

[@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

[@HindOpticals]

What does the Value 43 indicates?

[@LaramyKOptical]

That is axis or notation of position of cylinder. See the other videos or join OpticianWorks.com. John

[@HindOpticals]

@@LaramyKOptical I had a feeling it had something to do with axis. Thanks for clearing it out John.

[@avijitsarker9191]

This was very helpful 😍 Thanku

[@dary41187]

Love your videos, very helpful for this new optician apprentice. I have a question about the formula for the compound hyperopic astigmatism. I see a plus and a minus power. Is that correct?

[@LaramyKOptical]

Oops... no. Sounds like you need to hit the website! OpticianWorks.com best $99 you'll spend this year. Mixed astigmatism is corrected with the lens with both plus and minus powers. John

[@dary41187]

@@LaramyKOptical thank you, I actually just purchased the year for $99. But I was wondering about the compound hyperopic astigmatism, instead of the mixed astigmatism. Thanks again😊

[@LaramyKOptical]

Thanks --- Take your time. Follow the instructions (all of them) and I'll be here for you. John

[@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.

[@rashifarsya]

Thank you Sir, you're so helpful

[@cl-optix]

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

[@LaramyKOptical]

kzbin.info/www/bejne/kF7JYZ5spZeKY9k

[@amandaheller9746]

The prescriptions in the corner are very helpful thank you. I once got a prescription for glasses with astigmatism correction in them alone because I liked the freedom contacts gave me without peripheral distortion, but I had an astigmatism and couldn’t get used to my toric lenses, so, I was given glasses with just an astigmatism correction in them alone to put over my contacts at times when I just needed to see a little more sharply. I no longer have a copy of that glasses prescription or the glasses, so I don’t know what that prescription looked like. Would you be able to give me an example of what a prescription for astigmatism alone would look like? Also is it possible a person is neither myopic or hyperopic naturally and only needs this astigmatism correction only for their eyes? What would you call that then? Just plain astigmatism with no word in front of it? Thank you!

[@LaramyKOptical]

Sure. Drop me an email through the OpticianWorks website. Please include anything that you do know about current lens powers.

[@jimhaggard7436]

It would be simple myopic astigmatism. It sounds like you have compound myopic astigmatism with the myopia corrected for by contacts and the left over astigmatism corrected in your glasses for occasional use.

[@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

[@justbeautiful3083]

thank you

[@sakinamasud5392]

Nice 7 types welexplained

[@manikantamanish4095]

Thank you sir

[@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!

[@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!

[@prashantkuril.6698]

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

[@LaramyKOptical]

OpticianWorks.com

[@Ciaraluv13]

I wish these were put on the Optical cross for further viewing

[@LaramyKOptical]

Hmmmm... not a bad idea. If I ever do a reshoot I'll include that. John

[@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

[@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

[@l.waltermenezes8156]

AWESOME!

[@mohammadkh5968]

thanks alot it was so useful 😀

[@LaramyKOptical]

Glad we could help, Mohammad. Thanks for watching!

[@LaramyKOptical]

Thanks love hearing that! John

[@iPsychoxMacz]

Starting training

[@yourfavouritesongsalllangu1857]

thanks. 😊 Nice work

[@LaramyKOptical]

You are welcome. John

[@samarfaisal7975]

Amaaazing

[@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

[@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

[@jovithaj3676]

Thank u so much sir

[@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

[@marjan639]

Saved my life thanks !

[@LaramyKOptical]

Wow, that would be a first --- but it makes me feel good! John

[@rowidaibrahim8284]

Perfect 🥀

[@muhammad.hameem]

What about conical cornea???

[@LaramyKOptical]

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

[@muhammad.hameem]

@@LaramyKOptical can you please explain.

[@RehamAlshehri-k6c]

I LOVE THIS

[@ekyshwaryasigirisetti3691]

awsome and expecting some more vedios

[@LaramyKOptical]

You did see the other 72 of them right?

[@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

[@aboodalkaddah4758]

Thaaanks!

[@doublevision.productions]

amazing teacher!!

[@LaramyKOptical]

Thanks! John

[@carlossolorzano361]

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

[@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.

[@LearnQuran820]

Please do more videos on clinical optics

[@LaramyKOptical]

Waleed, Give me a little more to go on here.... John

[@donaldturner6402]

Confirmed cool cognition

[@zeinabsaad6204]

Thanks

[@LaramyKOptical]

You are welcome.

[@audiobibles4asia]

Well done thx :)

[@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