Eye Optics Lecture

This video covers the basic optics you need to know to understand basic glasses prescriptions.

length: 24:00 minutes

When I began my ophthalmology residency, I had no idea how to read or write a glasses prescription. In this video, I try to explain the basic topics I wish I had known. This includes lens theory, basic spherical problems (near and far-sightedness), astigmatism, cylinder conversion, and presbyopia (bifocals). While this lecture is “basic” and assumes you have no prior glasses experience … this is still important stuff. I hope you find this useful!

Screen Captures from this Video:

Glasses Prescription
The goal of this video is to completely understand what a glasses prescription
entails.

Prism Lens
A lens can be thought of as two prisms … that either converge or diverge light.

Lenses
A lens rack. The red lenses are "minus" while the black lenses are
"plus"

Loose Lens Refraction
Lenses are marked with diopter power.

Diopter Definition
Definition of a diopter is demonstrated, along with lens stacking to create
more powerful convergence.

Corneal Power
The eye has an overall power of approximately 60 diopters.

Hyperopic Child
Children tend to be slightly hyperopic as they have small eyes.

Corneal Astigmatism
Astigmatism is when the corneal surface is more "round like a football"
and less like a basketball.

Corneal Astigmatism
Children have "with the rule" astigmatism, while elderly tend to have
"against the rule"

Manifest
The three measurements we check when using the phoropter to "manifest"
a patient

Converting Cylinder
Converting a prescription to minus cylinder

Lens Accomodation Ciliary Body
Accomodation of the lens inside the eye

Presbyopia after cataract
Presbyopia makes it hard to see near objects.

bifocal
Bifocal power. We rarely prescribe greater than 3 diopters as few people read
much closer than 1/3rd of a meter (33 centimeters).

 


Comments and Feedback
24 Comments »


Thankyou was great find this info

Comment by Rafyte — March 16, 2010 @ 5:50 pm


Perfect.you know what exactly we need to know.very practical.
THANK YOU SO MUCH

Comment by Shahram — April 7, 2010 @ 5:49 pm


thanq

Comment by prasad — August 5, 2010 @ 10:24 am


i loved it , it is fantastic

thanks alot :)

Comment by Anoud — September 2, 2010 @ 12:15 pm


I’m in my last year of med school and still learned a lot from your video. It’s amazing how you can make these topics so simple to understand. I really wish I had more professors like you! Thank you for your time!

Comment by Joe — October 26, 2010 @ 6:08 pm


it is fantastic

Comment by Dr,Mony — January 11, 2011 @ 5:57 pm


GREAT!!! =)

Comment by alma — February 26, 2011 @ 5:21 pm


Wow, this is how you nail a subject. I just graduated from medical school and this helped a lot.

You just helped some patients. Thank you soo much!!

Comment by Elias Collado — March 13, 2011 @ 1:24 pm


Sir, this is great.
Thank u so much
love this website n ur teaching style too!!!!!!!!

Comment by Rajsekhar — April 6, 2011 @ 2:31 pm


thank you very much. i love this site and have learnt alot from here. i want to be ophthalmology surgeon. i’m so happy.
thank you again.

Comment by mohamed Haibeh — April 7, 2011 @ 1:56 pm


Dear Dr.

I truly appreciate your time and diligence making such an informative video for students such as ourselves. It was clear concise and an addendum to our school lectures. I would be interested in discussing with you about making future educational videos for students. Please contact me at your earliest convenience.

Thank you

Comment by jcw — April 28, 2011 @ 7:24 pm


thanks for this helpful video
you did a great job
keep it up
i really appreciate it.

Comment by MUFRACACA — June 10, 2011 @ 4:54 pm


Fantastic Very much…….. very much fantastic………………

Comment by drbillal — June 26, 2011 @ 3:00 pm


Brilliant video! You are a natural teacher.

Comment by Sui — July 14, 2011 @ 4:39 pm


you are simply genious. thanks

Comment by akas — August 11, 2011 @ 11:53 pm


thanks a lot.this definitely manages to converge optics in everyone’s brains

Comment by Neeraj — August 23, 2011 @ 11:29 am


if we learn some vedeo on ophthalmic lenses (glasses )property ,its very nice lecture

Comment by sami — September 12, 2011 @ 11:16 pm


hi, i am a doctor, and i love your classes. Thank you for doing this, that help me a lot. From Costa Rica.

Comment by mei — September 16, 2011 @ 7:15 pm


thanks a lot

Brilliant video

:) :) :)

Comment by dd — October 14, 2011 @ 9:09 am


thank you Dr.Thimothy, this video & other staff in brilliant website are treasure for ophthlmic residents.. I wish i found this site when i was in my 1st yr.. anyway im not too late, im 2nd yr now;)

Comment by Dr.Omar Khudruj — November 10, 2011 @ 10:10 am


thank you sir its really amazing its my first time to understand correction in this fascinating way

Comment by night walker — December 14, 2011 @ 4:07 pm


you are amaaaaaaazing
thanks alot..

Comment by saud10 — December 19, 2011 @ 5:04 pm


GREAT VIDEO!THANK YOU VERY MUCH

Comment by prashant — January 22, 2012 @ 10:15 am


excellent website, very helpful. thank you!

Comment by nir — January 30, 2012 @ 8:24 am


Leave a comment