Dr. Bullimore Digital Infinite Refraction Interview

Q & A with Dr. Mark Bullimore on the evolution of refraction tools and the Digital Infinite Refraction method

[@stefcep]

Of course you can adjust the sphere power to keep the spherical equivalent power constant using a traditional analogue phoropter- the rule is for every -0.50D increase in cylinder add +0.25 sphere. Optometrist have been doing it for 100 years. Trial frames also have 0.12 D sphere and cylinder increments and + -0.25 JCC's for additional precision and cost a fraction of this machine. if the patient can pick the difference. Could the good doctor post links to independent peer-reviewed publications not paid for by the manufacturer confirming the "overwhelming" results? Oh and very few outside of British optical chains rely on or use air puff tonometers... root canal and colonoscopy, I've had both, I'll take the gruelling 3 minute subjective refraction any day.

[@kennypowers1011]

Why would you need, or want, to refract someone to 0.01D? How do you account for changes in the tear film, which can easily be 0.12D or more? Which pupil size do you choose to refract someone with this level of precision? Most phoropters don't have 0.01D because that level of precision is not necessary. Most patients can't tell the difference between 0.25D, so how can you even get a patient down to 0.01D with a subjective exam with any level of accuracy? You don't measure your height in millimeters. It's even worse for the eye because the eye is not a static system, the tear film changes, the pupil changes and both of these things can affect the refractive error by multiple quarter diopter steps throughout the day. There's some wavefront aberrometers that can objectively measure to 0.01D, but this can be helpful if you find someone between two 0.25D steps. That way you can refer to this during the subjective and if they're close, choose the more plus of the 0.25D steps that they're between, so as to not over-minus and move on.