EP: Prof Barrett: Developing RayOne EMV and the Barrett Universal Formula


Dr Karl Stonecipher (US) meets with Professor Graham Barrett (Australia), to learn more about his partnership with Rayner, developing RayOne EMV. Their conversation delves into the concept behind RayOne EMV, the incorporation of positive spherical aberration to enhance depth of focus, the process of patient selection, and the lens‘ applicability for a wide range of patients.


Dr Karl Stonecipher (host)
Dr Karl Stonecipher is the medical director of TLC Greensboro in North Carolina and a clinical associate professor of Ophthalmology at the University of North Carolina. Dr Stonecipher has over 100 abstracts, articles, and book chapters published, and speaks both nationally and internationally on refractive, cataract, presbyopic and refractive surgery.

Prof Graham Barrett (guest)
Professor Graham Barrett is a consultant ophthalmologist at the Lions Eye Institute as well as Sir Charles Gairdner Hospital in Perth Western Australia and is a clinical professor in the University Department of Ophthalmology of Western Australia. His special areas of interest include cataract and implant surgery, as well as corneal and keratorefractive surgery. Professor Barrett is also the founding and current President of AUSCRS.

Key Takeaways:

  • RayOne EMV uses positive spherical aberration which interacts synergistically with myopia to give an extended range of vision without impacting distance vision.
  • Professor Barrett discovered that using positive spherical aberration with myopia achieves a better quality of vision.
  • If surgeons are unsure about using RayOne EMV on a patient, Professor Barrett suggests checking the amount of spherical aberration in the eye and being cautious if it nears +0.3 to +0.4 microns.
  • Professor Barrett believes the RayOne EMV lens is suitable for almost anyone.
  • Today, many patients are more concerned with being spectacle free for intermediate vision, so that they can use their smart phones and tablets.

Additional Resources:

My Next Ophthalmologist Needs No Introduction: Ep 2 with Prof Barrett

The Best of Both Worlds by Professor Graham D Barrett

Find out more about RayOne EMV

RayOne EMV