Optics Concepts Lecture

This lecture covers some basic optics principles such as refraction, diopters, and common vision problems faced in an eye clinic. This was recorded at the HOPS ophthalmic technician conference in Daytona Beach.

Snapshots from this lecture:

Evolution of eye
I explain the evolution/creation of the eye, from the simple pinhole eye of this nautilus, to the more complex lens system that we use today.
Prism Pink Floyd
Pink Floyd’s album cover can tell us a lot about refraction..
Staking diopters
This video segment explains lens diopter power, and how lenses can be stacked.
Converting power
How we convert from our prescription to the power-cross and back. This also explains the difference between using “plus cylinder” and “minus cylinder” in our prescriptions.
Accomodation and presbyopia
A video demonstrating accomodation, and explaining why children with congenital cataract surgery need bifocals.
How do blue-blocker glasses work
Demonstrate how blue-blocker sunglasses remove chromatic abberation and improve perceived vision.
Why is vision blurry underwater
Understanding underwater vision to better understand the power of the cornea.
Snells law
A great magic trick … Snell’s law being broken.

Dr. Timothy Root is a practicing ophthalmologist and cataract surgeon in Daytona Beach, Florida. His books, video lectures, and training resources can be found at:


  1. Hey Tim,

    Enjoying your videos.

    Ever think of making some of your videos in regards to OKAP review material? It would be a great way for ophthalmology residents (like myself) to study for the exam.

    Take care,

  2. Thgank you sir,

    These are indeed very informative videos.
    Kindly keep sending some more.

    I just changed my e-mail ID and would like to have future interaction to your site with the above mentioned g -mail ID.

    Thank you

  3. Dr. Tim,

    I love your videos, they are very very well done, it means you master slit lamp and digital video editing, an so they are a very nice source to learn more tricks and things that we can do with slit lamp, thanks for that.

    I am an optometrist who works in Ecuador (South America), where optometric education is very poor, but your videos have taught me a lot and motivated me to buy a beam splitter and to adapt a video digital camera and a SLR camera, expensive for me, but I hope someday make great videos like yours. You have been an inspiration for me.

    Thanks also for other videos like “Optics Concepts” or “Twenty Eye Exam Tricks for Tricky Patients”, very easy and nice to follow.

    Sorry for my English, I hope you understand, and again thanks so much, please continue your work.

  4. dr.tim
    i loved your videos very much
    please i need all your videos
    please publish more as your videos are very useful
    thank u dr

  5. Hi Tim… you are a “master” teacher…!!
    I love teaching as well…
    i would love to make cartoon videos for better teaching… how do you do that? can you give me tips or teach me how to do it? or maybe you can make a video about how to make videos !

  6. DR.TIM:

  7. i want to see each video of eye lecture because your explanatoin is so good that every one can understand without facing any difficulties but icould not see some video like OPTICS, TRAUMA in ophthabook.com and vimeo.com how could i see this video in you tube you r my favorite teacher for understanding eye and its disease

  8. whit this way of teaching, slide presentation is not attractive any more. and we don’t know what to do in the other fields of medicine (e.x: hematology)

  9. Dr Tim,
    You are the best ophthalmology teacher in the world. The way you teach is innovative and stupendous! kindly, be our benefactor all your life and keep these things free of cost
    😛 Thanks a gazillion! i wish u were in my med school 🙁

  10. Dear Dr. Root,
    thank you for presenting basic ophthalmologic information in this very comprehensive format.

    Merry Christmas and a happy enw year


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