Protecting Sight #137: How Khan Academy reinvented education. Pterygium peeling technique, negative dysphotopsia, reverse optic capture, and an embedded retinal eyelash. Leonardo’s Codex on birds & flight.

Welcome to my daily learning journal. My daily goal is to watch one Ted Talk and one cataract surgery. I also plan to read one journal article and read/listen to a book chapter, short story or significant work.

Here’s today’s list:

1. Ted Talk – Sal Khan: Let’s use video to reinvent education. “Salman Khan talks about how and why he created the remarkable Khan Academy, a carefully structured series of educational videos offering complete curricula in math and, now, other subjects. He shows the power of interactive exercises, and calls for teachers to consider flipping the traditional classroom script — give students video lectures to watch at home, and do “homework” in the classroom with the teacher available to help.” (

A phenomenal 2011 Ted Talk. Sal Khan has revolutionized online learning.

2A. Cataract Surgery – Uday Devgan MD – Amazing Pterygium Peeling Technique.

2B. Cataract Surgery – Richard Mackool MD – Episode 22: Negative Dysphotopsia: Reverse Optic Capture Techniques. Dr. Mackool writes in part, “This patient has persistent negative dysphotopsia after cataract-implant surgery performed 18 months ago. A combination of techniques is used to achieve the desired reposition of the IOL optic (reverse optic capture).”

Figure thumbnail gr1

3. Journal – Ugradar S, Rootman DB, Khan MA. Embedded Retinal Eyelash with Orbital Inflammation. Ophthalmology. 2020 Oct;127(10):1394. doi: 10.1016/j.ophtha.2020.06.008. PMID: 32951676.

Flying machine, c.1487 - Leonardo da Vinci

4. Book Chapter – Leonardo da Vinci by Walter Isaacson. Chapter 11, “Birds and Flight.” See also “Leonardo da Vinci’s Codex on the Flight of Birds” from the Smithsonian.

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