waleed, We do cover the lensmeter in a multi-part video series. You should find them on the Laramy-K RU-vid channel. Sorry nothing on retina-scopes of any kind. That is outside the area of opticians here in the US. In other parts of the world, yes, here we stop where the cornea begins.
Hello, "redirecting" light is the same thing as "bending" light. From my understanding, many people use the terms "redirect" and "bend" interchangeably with "refract" when talking about the change in direction of light rays. The lens both inside the eyeball and on eyeglasses are transparent materials that refract, redirect, or bend light. Your diagrams did help me visualize this concept though...thanks.
Hi. I've got a question for you. My 11-year-old nephew has just been told he needs to wear glasses for a year, to strengthen his eyes, after which he will apparently be able to stop wearing them for ever. How is this possible? If he walked around on crutches for a year, his legs would become weaker, not stronger, so how is it different when it comes to eyes and glasses?
That is outside the scope of an optician. An optometrist or ophthalmologist might suggest it but I'm not about to question the why behind it. Now if the glasses have prism then it can force the eye to hold a different position thus "strengthening" the correct alignment. As to glasses making eyes weaker or stronger --- the jury is still out on that one. John
You are an inspiration. I truly enjoy watching all your videos and I have no more doubts....... I will enroll in your course and I will try to become the best optician I can with your help and with your passion for teaching. Thank you very much. Muchas gracias from Japan.
I am a 60 year old new optician. I love your videos for their information and entertainment. They help me with my customers, help me verify lenses, help me to understand and tell people about their refractive errors and how we can help them. I work for one of the largest (top 3) optical stores in the US. People who come to get glasses in our store are often unsure why they can't see and what we are doing to 'fix it'. They enter the store clutching a bit of paper with numbers they do not comprehend. Your diagrams help me to help them to understand. I love explaining to a little 5 year old boy why he can see better with his glasses or to a lovely 40 year old woman why she might like to have a bifocal or progressive lens. No greater joy than when the patient puts the lenses in front of their eyes and says, "I can see!" First time wearers bring tears to my eyes, as little baby fists try to push the glasses away, but then realize that they can suddenly see. The first thing they do is turn to their mother's face. No greater moment. Thank you.
I just started an optician program offered through my work, but it's all online and I was really struggling with grasping the concepts. I was on the verge of quitting until I found your videos. Getting to see what I"m trying to learn has improved my comprehension tremendously. Thank you!
Your diagrams are misleading and confusing. First, no significant light bending takes place, except at the cornea/eye lens, and at the corrective lens. Myopia diagram should show rays coming in PARALLEL from the left side object, to the cornea/eyelens where they are bent converged, then proceeding STRAIGHT to the retina where they meet at a point (for normal vision) or meet and cross in front of the retina (for myopia). For corrected myopia, the rays come from the left PARALLEL, pass through the corrective lens, where they are bent divergent then STRAIGHT to the cornea/lens where they are bent converged, going STRAIGHT to the retina, meeting at a point. On all but the most extreme cases, almost all of the bending takes place at the cornea. Here is link to correct diagram eduladder.com/viewquestions/6730/Describe-with-a-ray-diagram-how-a-person-with-myopia-can-be-helped-by--spectacles--2005-CBSE-Physic-class-10 (Hyperopia diagram at that site is also flawed). The rays are PARTIALLY converged by the corrective lens, then usually MOST of the convergence bending takes place at the cornea/lens. Elsewhere, the rays are STRAIGHT. It needs to be emphasized that these diagrams show the rays from only one point on the object. The image is made up of a huge number of these bundles, each arriving at a different angle to the eye, and landing on different parts of the retina. A most useful video would be to set up optical bench and lenses and model the eye in full scale. You can use pin-source and smoke to show light rays, and small screen for retina. Never have I seen such material available, so this would stand out.
Brian, I can't say how sad I am to see this from you. As I would reply to any other --- if you can do better then please do. Heck, make your own series of videos and if they are better than what I produce I'll gladly point people your way. I added Disclaimer 1 and then repeated it again for a reason. We just don't play this way here so maybe it is time to move on? I'm sure you can find a social media group worthy of you. John
I mean no harm. Your site is a wonderful source of optical information, which is relied upon by many. What I am trying to prevent is the propagation of misleading information (I found plenty of it when searching for a good diagram how the light propagates). Everything you say is 100% correct, but the ray diagram misleads. (You even drew an arrow correctly, but then hastily removed it). Don't you want your site to be accurate? Or should I find a way to make these statements to you without creating a social scene? (as having knowledge of physics and optics, I feel this is important, to be able to visualize what is happening. What would Steve Machol say?) The reason I am commenting is I feel your site renders a useful service and is "worth it". Is there a more constructive way for me to do this, or should I give up and buzz off?
Brian, Listen to Disclaimer 1 and then listen to it again when I repeat it. It was repeated because I was 100% certain that someone (most likely you) would pop up and say they were wrong. Ask Keith, I insisted that he leave in the repeat! These are concepts presented at a level for beginner opticians. I never (ever) claim a understanding of physics or optics for that matter. If I was here preaching from a pedestal and acting like a know-it-all or pretending to be an engineer or physicist then have at me! From the very first video I have been as open and honest about my level, my math skills and saying straight up that this is, "how I understand this stuff." It seems to help others so I keep doing it. If you watch all the videos you will see several where I do complete red-faced mea-culpas. If I'm wrong, I'm wrong and I admit it in public. I know you don't believe me but if you can do better, please do so and I'll point people to your videos. Heck if you want some tips on getting started, equipment etc, drop me an email. You might try checking outThe Optical Society on Facebook it may be more like what you are looking for? Walking away now... John
This is really helpful I'm just an apprentice optical assistant but watching your vids are very educational so yh please keep bringing stuff out I would really love a video about the different layers or the eyes and how they function with each other. 😊
Jack, You will need to look around for that one. Maybe under certified ophthalmic assistant or COA? OpticianWorks is all about moving away from the "opticians in healthcare" model and moving us towards the "opticians in business" model instead. If it weren't for anatomy being on so many optician exams I wouldn't even cover it at all. Knowing the layers of the eye and/or the retina gives us a warm fuzzy feeling but does absolutely nothing to elevate the profession of optician. Heck, I had to do a full, real, semester long, dissection biology class during my program. Why? I'll never, ever know! Don't get me wrong if that is of interest to you then go for it! But it isn't something I'll ever be covering. John
Flat transposition gives us +2.25 -1.25 X 90 you have + power in both principle meridians and you have 1.25 cylinder so compound hyperopic astigmatism. There is another video that covers the refractive conditions.
Meryem, That section is being worked on right this minute. Look for an entire new section on the OpticianWorks website in early December (or maybe a little sooner). John
That kind of depends on many things. Short answer is, "nothing." Long answer involves material, strike angles, curvature, plate, etc. But any combination of front and back that equals 0 the light passes through as if the lens "wasn't there" or "isn't there." (a window)
Thank you for explaining this. I have Anti reflective coating on some of my prescription glasses, and sometimes it interferes while viewing certain types of surfaces, which can be a pain. I can see how it could be a positive on watches and also a negative, I have Anti reflective coating on some of my watches, and some do not.
How can you tell the difference between a compound hyperopic astig and a mixed astig from looking at the RX examples (if there weren't any diagrams shown)? The RX's look extremely similar to me. Thanks!
Going through your training program on optician works site confused why this video isn't included right at the beginning.... Working through more difficult videos and hadn't seen this one yet ... or the one about some of the terms. Did I somehow miss it? If not it should be included before one gets too far in!
Just a head scratcher here....How come the light doesn't bend toward the base on a 'minus lens'? Thanks for your videos, still trying to pass the ABO for Costco.
@@LaramyKOptical I’ve been using the videos and other sources. I was just curious on the illustrations shown in this particular video. I’m still working at it though.
No because basically there is no such thing. Some people are born that way and it works for them. Mono-vision contact lenses can work, sometimes. Have some people been successful doing mono-vision glasses? Yeah a few, but it is not a commonly accepted practice.
Ok then, been fun watching ya John, but, why do opticians make so little money? Taking my degree in optics, getting back in my truck to get retirement cash, poverty wages just ain't my thing!
I hear ya! Why do opticians make so little? Lack of any national standard, no consistent demand for a specific defined skill set, no unions and well really hard to kill anyone with a pair of glasses. Just IMO! John
OR because opticians are entirely too focused on dispensing rather than being indispensable, on doing a job rather than providing and creating value. There is more money to be made on the eyewear side of the house than the medical side. There's a reason opticians aren't getting much of it. -Keith
