John Berdahl, MD

John Berdahl, MD is a board-certified ophthalmologist at Vance Thompson Vision in Sioux Falls, South Dakota, and a professor at the University of South Dakota, specializing in cataract, cornea, glaucoma, and refractive surgery. He trained at Mayo Medical School, Duke University, and Minnesota Eye Consultants, and is one of a rare few U.S. surgeons with fellowship training across cornea, glaucoma, and refractive surgery. An award-winning researcher and published author, Dr. Berdahl is also dedicated to global eye care access through surgical mission work and leadership in programs serving underserved communities.

Articles by John Berdahl, MD

Beyond the basics: John Berdahl, MD, on AI-driven IOL planning, PCO prevention, and lessons from the mission field

ByJohn Berdahl, MD,Lucia Gambuzza

June 12th 2026

In part 2 of a 2-part Q&A, John Berdahl, MD, weighs in on AI-driven IOL power calculation in challenging eyes, best practices for reducing posterior capsule opacification, and how surgical mission work abroad has shaped his approach in the OR.

Closing the gap: John Berdahl, MD, on the global cataract burden and the emerging dementia connection

ByJohn Berdahl, MD,Lucia Gambuzza

June 5th 2026

In part 1 of a 2-part Q&A, John Berdahl, MD, discusses the widening global cataract surgical gap and examines emerging evidence linking cataract extraction to a reduced risk of dementia.

AAO 2025: Which lens to consider in patients with pseudoexfoliation

ByJohn Berdahl, MD,Sydney M Crago,Sheryl Stevenson

October 19th 2025

John P. Berdahl, MD, discusses advanced lens options for patients with pseudoexfoliation, highlighting considerations for successful longterm outcomes.

(Image credit: AdobeStock/MarekPhotoDesign.com)

(Part 2) From ophthalmology’s lockdown to lasting change: The pandemic habits that stuck

BySheryl Stevenson,Peter J. McDonnell,Nicole Bajic, MD,John Berdahl, MD,David A. Eichenbaum, MD, FASRS,Ehsan Sadri, MD, FACS,Oluwatosin U. Smith, MD,James C. Tsai, MD, MBA

April 24th 2025

From revised patient flow to smarter tech adoption, ophthalmologists share which changes from 2020 have become cornerstones of modern care—and how they’re preparing for the next big disruption

(Part 1) From ophthalmology’s lockdown to lasting change: Five Aprils ago

ByPeter J. McDonnell, MD,Nicole Bajic, MD,John Berdahl, MD,David A. Eichenbaum, MD, FASRS,Ehsan Sadri, MD, FACS,Oluwatosin U. Smith, MD,James C. Tsai, MD, MBA,Sheryl Stevenson

April 24th 2025

Ophthalmologists reflect on the transformative impact of COVID-19, highlighting adaptations in patient care, safety protocols, and the rise of telemedicine.

Glaucoma devices and pharmaceuticals with John Berdahl, MD

ByJohn Berdahl, MD,Sydney M Crago

February 7th 2025

John Berdahl, MD, discusses a non-surgical, non-drug treatment for glaucoma approved by the FDA in 2024. The pump uses negative pressure to lower eye pressure by an average of 39% in clinical trials, with a good safety profile.

CXL demands continuity of care

ByJohn Berdahl, MD

October 15th 2017

Crosslinking meets the previously unmet needs of progressive keratoconus patients and provides an opportunity to increase engagement with optometrists, explain John Berdahl, MD, and George O. Waring IV, MD.

Exploring risk, reward in trabecular bypass, suprachoroidal devices

ByJohn Berdahl, MD

January 1st 2017

Though much focus for stents has been in the trabecular meshwork, many companies are currently developing suprachorodial devices, which are in various stages of FDA review.