Appendix E: Refraction equipment

Objective refraction	Subjective refraction
Shutterstock.com	$Picture of an autorefractor with a front view and side view$ Shutterstock.com	Shutterstock.com	Shutterstock.com
Retinoscope	Autorefractor	Universal frame with trial lenses	Phoropter
The eye professional shines a light into the patient’s eye and sees how the light is reflected from the retina.¹⁵⁸	Automated machine which calculates the refractive error by detecting how the patient’s eye influences infrared radiation sent into the eye.¹⁵⁹	The eye professional inserts trial lenses into a frame that allows for variable adjustments such as interpupillary distance or side length.	Mechanical device combining many switchable lenses into a single system which allows the eye professional to quickly alternate lenses until the best is found.¹⁶⁰
Around USD300-USD500	Around USD10,000- USD15,000	Around USD300- USD700	Around USD1,000-USD3,000

Cordero, I. Understanding and looking after a retinoscope and trial lens set. Community Eye Health; 2017.↩︎
Keirl, A, Christie, C. Clinical optics and refraction: a guide for optometrists, contact lens opticians and dispensing opticians. Elsevier Health Sciences; 2007.↩︎
Durr, NJ, Dave, SR, Lage, E, Marcos, S, Thorn, F, Lim, D. From unseen to seen: tackling the global burden of uncorrected refractive errors. Annu Rev Biomed Eng. 2014;16(1):131-153.↩︎