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Quality of eyeglass prescriptions from a low-cost wavefront autorefractor evaluated in rural India: results of a 708-participant field study
  1. Nicholas J Durr1,
  2. Shivang R Dave2,
  3. Daryl Lim2,
  4. Sanil Joseph3,
  5. Thulasiraj D Ravilla3,
  6. Eduardo Lage2,4
  1. 1Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland, USA
  2. 2PlenOptika, Inc, Boston, Massachusetts, USA
  3. 3Lions Aravind Institute of Community Ophthalmology (LAICO), Aravind Eye Care System, Madurai, India
  4. 4Department of Electronics and Communications Technology, Universidad Autónoma de Madrid, Madrid, Spain
  1. Correspondence to Dr Nicholas J Durr; ndurr{at}


Objective To assess the quality of eyeglass prescriptions provided by an affordable wavefront autorefractor operated by a minimally trained technician in a low-resource setting.

Methods and Analysis 708 participants were recruited from consecutive patients registered for routine eye examinations at Aravind Eye Hospital in Madurai, India, or an affiliated rural satellite vision centre. Visual acuity (VA) and patient preference were compared between trial lenses set to two eyeglass prescriptions from (1) a novel wavefront autorefractor and (2) subjective refraction by an experienced refractionist.

Results The mean±SD VA was 0.30±0.37, –0.02±0.14 and −0.04±0.11 logarithm of the minimum angle of resolution units before correction, with autorefractor correction and with subjective refraction correction, respectively (all differences p<0.01). Overall, 25% of participants had no preference, 33% preferred eyeglass prescriptions from autorefraction, and 42% preferred eyeglass prescriptions from subjective refraction (p<0.01). Of the 438 patients 40 years old and younger, 96 had no preference and the remainder had no statistically significant difference in preference for subjective refraction prescriptions (51%) versus autorefractor prescriptions (49%) (p=0.52).

Conclusion Average VAs from autorefractor-prescribed eyeglasses were one letter worse than those from subjective refraction. More than half of all participants either had no preference or preferred eyeglasses prescribed by the autorefractor. This marginal difference in quality may warrant autorefractor-based prescriptions, given the portable form factor, short measurement time, low cost and minimal training required to use the autorefractor evaluated here.

  • diagnostic tests/investigation
  • optics and refraction
  • vision
  • public health

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  • NJD and SRD contributed equally.

  • Contributors NJD and SRD contributed equally as co-first authors. NJD, SRD, DL, EL, SJ and TDR designed the study. NJD, SRD, DL and EL contributed to the technical design of the autorefractor prototype. NJD analysed the data and prepared the manuscript. SRD and DL trained the autorefraction technician and organised the study facilities. SRD and SJ oversaw the recruitment and data collection. DL and EL contributed to the data analysis.

  • Funding This work was financially supported by a grant from the United States–India Science & Technology Endowment Fund (USISTEF) awarded jointly to PlenOptika and Aurolab. Financial support for the initial autorefractor development is gratefully acknowledged from Comunidad de Madrid through the Madrid-MIT M+Visión Consortium. These funding sources had no role in the design or execution of the study. Research relating to the autorefractor reported in this publication was partially supported by the National Eye Institute of the National Institutes of Health under Award Number R43EY025452 and R44EY025452. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

  • Competing interests NJD, SRD, DL and EL are inventors on patents relating to the autorefractor used in this study and have a financial interest in PlenOptika. SRD and DL are employees of PlenOptika. NJD and EL are technical advisors and collaborators of PlenOptika.

  • Patient consent for publication Obtained.

  • Ethics approval Aravind Eye Care System Institutional Review Board (Project Code RES2014065PDT) approved the study protocol.

  • Provenance and peer review Not commissioned; externally peer reviewed.

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