Comparison of refractive assessment using Hartmann-Shack and ray-tracing wavefront aberrometry, autorefraction, and subjective refraction
Medical hypothesis, discovery & innovation in optometry,
Vol. 7 No. 2 (2026),
24 July 2026
,
Page 67-72
https://doi.org/10.51329/mehdioptometry247
Abstract
Background: Accurate objective assessment of refractive error is essential for efficient clinical refraction and optimal spectacle prescription, particularly with the growing use of wavefront-based technologies in contemporary ophthalmic practice. We aimed to compare refractive measurements obtained by subjective refraction, conventional autorefractometry, Hartmann-Shack wavefront aberrometry (WASCA), and ray-tracing wavefront aberrometry (iTrace) in healthy young adults, and to evaluate the suitability of each objective modality as a starting point for subjective refraction.Methods: This study included healthy adults aged 18–30 years, recruited at Nethradhama Superspeciality Eye Hospital, Bengaluru, India, between October 2021 and June 2022. Participants underwent comprehensive ophthalmic examination followed by refractive assessment using subjective refraction, autorefractometry, WASCA Hartmann-Shack wavefront aberrometry, and iTrace ray-tracing wavefront aberrometry under non-cycloplegic conditions. Spherical equivalent (SE) measurements obtained by the four modalities were compared using repeated measures analysis of variance with Tukey honestly significant difference post hoc testing. A one-sample t-test was used to determine whether the mean difference between subjective refraction and autorefractometry differed significantly from zero.
Results: The study cohort comprised 60 healthy adults (120 eyes) aged 18–30 years, 24 males (40%) and 36 females (60%), with a mean (standard deviation [SD]) age of 21.4 (1.4) years. Significant differences in SE measurements were observed among the four modalities for both right eyes (RE) and left eyes (LE) (both P < 0.05). In the RE, mean (SD) SE values were -0.65 (0.81) D for subjective refraction, -0.74 (0.89) D for autorefractometry, -0.98 (0.88) D for WASCA, and -1.15 (1.26) D for iTrace. Corresponding LE values were -0.54 (0.92) D, -0.67 (0.79) D, -0.94 (0.84) D, and -1.24 (0.97) D, respectively. Post hoc analysis revealed significant differences between subjective refraction and both WASCA and iTrace measurements in both eyes (all P < 0.05), whereas differences between subjective refraction and autorefractometry were not statistically significant (both RE and LE P > 0.05). The mean inter-method difference between subjective refraction and autorefractometry differed significantly from zero in both eyes (RE: 0.09 [0.32] D, LE: -0.13 [0.50] D; both P < 0.05).
Conclusions: Autorefractometry produced refractive measurements that were closer to subjective manifest refraction than those obtained with either Hartmann-Shack or ray-tracing wavefront aberrometry. Both aberrometers displayed a tendency toward more myopic refractive estimates. Although autorefractometry remains a practical and reliable objective starting point for subjective refraction, subjective refraction continues to represent the reference standard for final spectacle prescription.
Keywords:
- refractive error
- hypermetropia
- myopias
- myopic astigmatisms
- hyperopic astigmatism
- mixed astigmatisms
- vision test
- ocular refraction
- subjective refraction
- retinoscopies
- autorefractometer
- aberrometries
- optometry diagnostic techniques
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17. Al-Tuwairqi WS, Ogbuehi KC, Razzouk H, Alanazi MA, Osuagwu UL. Agreement Between Autorefraction and Subjective Refraction in Keraring-Implanted Keratoconic Eyes. Eye Contact Lens. 2017 Mar;43(2):116-122. doi: 10.1097/ICL.0000000000000244. PMID: 26825280.
18. Davidova P, Rostom M, Timoceanu LG, Schug T, Kaiser KP, Jandewerth T, Kohnen T. Subjective and Objective Refraction Using Autorefraction and Two Wavefront-based Aberrometers in Extended-Depth-of-Focus and Simultaneous Vision Intraocular Lenses. Am J Ophthalmol. 2026 May;285:335-342. doi: 10.1016/j.ajo.2026.02.023. Epub 2026 Feb 18. PMID: 41720231.
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20. Zhang X, Zhou Y, Yang J, Wang Y, Yang W, Gao L, Xiang Y, Zhang F. The distribution of refraction by age and gender in a non-myopic Chinese children population aged 6-12?years. BMC Ophthalmol. 2020 Nov 7;20(1):439. doi: 10.1186/s12886-020-01709-1. PMID: 33160315; PMCID: PMC7648976.
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22. Hastings GD, Marsack JD, Nguyen LC, Cheng H, Applegate RA. Is an objective refraction optimised using the visual Strehl ratio better than a subjective refraction? Ophthalmic Physiol Opt. 2017 May;37(3):317-325. doi: 10.1111/opo.12363. Epub 2017 Mar 30. PMID: 28370389; PMCID: PMC5469359.
23. Hervella L, Villegas EA, Prieto PM, Artal P. Assessment of subjective refraction with a clinical adaptive optics visual simulator. J Cataract Refract Surg. 2019 Jan;45(1):87-93. doi: 10.1016/j.jcrs.2018.08.022. Epub 2018 Oct 8. PMID: 30309774; PMCID: PMC6320260.
24. Bennett JR, Stalboerger GM, Hodge DO, Schornack MM. Comparison of refractive assessment by wavefront aberrometry, autorefraction, and subjective refraction. J Optom. 2015 Apr-Jun;8(2):109-15. doi: 10.1016/j.optom.2014.11.001. Epub 2014 Dec 11. PMID: 25498534; PMCID: PMC4401825.
25. Cooper J, Citek K, Feldman JM. Comparison of refractive error measurements in adults with Z-View aberrometer, Humphrey autorefractor, and subjective refraction. Optometry. 2011 Apr;82(4):231-40. doi: 10.1016/j.optm.2010.09.013. PMID: 21439490.
26. Bamdad S, Momeni-Moghaddam H, Abdolahian M, Piñero DP. Agreement of wavefront-based refraction, dry and cycloplegic autorefraction with subjective refraction. J Optom. 2022 Jan-Mar;15(1):100-106. doi: 10.1016/j.optom.2020.08.008. Epub 2020 Sep 28. PMID: 32896507; PMCID: PMC8712579.
27. Lin HZ, Chen CC, Lee YC. Comparisons of wavefront refraction, autorefraction, and subjective manifest refraction. Tzu Chi Medical Journal. 2013 Mar 1;25(1):43-6. doi: 10.1016/j.tcmj.2013.01.006.
28. Doyle M, O'Dwyer V, Moore M, Harrington S. Accuracy and repeatability of autorefraction in young adults: a comparison of cycloplegic and non-cycloplegic methods. Clin Exp Optom. 2026 Apr;109(3):462-472. doi: 10.1080/08164622.2025.2542321. Epub 2025 Aug 10. PMID: 40785048.
29. Roque A, Nunes AF, Nascimento H, Martinez-Perez C. Instrument-based, non-cycloplegic versus cycloplegic refraction in pediatric and young adult populations (?25 years): A systematic review and meta-analysis. Adv Ophthalmol Pract Res. 2025 Nov 14;6(1):56-67. doi: 10.1016/j.aopr.2025.11.004. PMID: 41647053; PMCID: PMC12870854.
30. Jones D, Chow A, Fadel D, Gonzalez Meijome JM, Grzybowski A, Kollbaum P, Loughman J, Wolffsohn J. IMI-Instrumentation for Myopia Management. Invest Ophthalmol Vis Sci. 2025 Jul 1;66(9):7. doi: 10.1167/iovs.66.9.7. PMID: 40600762; PMCID: PMC12227030.
31. Umaefulam V, Safi S, Lingham G, Gordon I, Mueller A, Krishnam NS, Alves Carneiro VL, Yu M, Evans JR, Keel S. Approaches for delivery of refractive and optical care services in community and primary care settings. Cochrane Database Syst Rev. 2024 May 29;5(5):CD016043. doi: 10.1002/14651858.CD016043. PMID: 38808577; PMCID: PMC11134311.
32. Shane TS, Knight O, Shi W, Schiffman JC, Alfonso EC, Lee RK. Treating uncorrected refractive error in adults in the developing world with autorefractors and ready-made spectacles. Clin Exp Ophthalmol. 2011 Nov;39(8):729-33. doi: 10.1111/j.1442-9071.2011.02546.x. Epub 2011 Apr 21. PMID: 22050561; PMCID: PMC4139100.
2. Kozlov Y, Kinori M, Armarnik S, Yahalomi T, Ekshtein A, Levian L, Mezad-Koursh D, Pikkel J, Ben-Ari O. Subjective versus objective refraction in healthy young adults. BMC Ophthalmol. 2024 Feb 20;24(1):79. doi: 10.1186/s12886-024-03340-w. PMID: 38378511; PMCID: PMC10877844.
3. Carracedo G, Carpena-Torres C, Serramito M, Batres-Valderas L, Gonzalez-Bergaz A. Comparison Between Aberrometry-Based Binocular Refraction and Subjective Refraction. Transl Vis Sci Technol. 2018 Aug 3;7(4):11. doi: 10.1167/tvst.7.4.11. PMID: 30087806; PMCID: PMC6075791.
4. Beesley J, Davey CJ, Elliott DB. Subjective refraction and prescribing styles used by UK optometrists. Ophthalmic Physiol Opt. 2025 Jul;45(5):1113-1125. doi: 10.1111/opo.13495. Epub 2025 Apr 3. PMID: 40178394; PMCID: PMC12153031.
5. Kaur K, Gurnani B. Subjective Refraction Techniques. 2023 Jun 11. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2026 Jan–. PMID: 35593807.
6. Enaholo ES, Musa MJ, Zeppieri M. Objective Refraction Technique: Retinoscopy. 2023 Oct 28. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2026 Jan–. PMID: 37983333.
7. Kemchoknatee P, Sunlakaviset P, Khieokhoen N, Srisombut T, Tangon D. A Comparison of Autorefraction and Subjective Refraction in an Academic Optometry Clinic. Cureus. 2023 Apr 11;15(4):e37448. doi: 10.7759/cureus.37448. PMID: 37182059; PMCID: PMC10174683.
8. Mukash SN, Kayembe DL, Mwanza JC. Agreement Between Retinoscopy, Autorefractometry and Subjective Refraction for Determining Refractive Errors in Congolese Children. Clin Optom (Auckl). 2021 Apr 21;13:129-136. doi: 10.2147/OPTO.S303286. PMID: 33907484; PMCID: PMC8071214.
9. Padhy D, Bharadwaj SR, Nayak S, Rath S, Das T. Does the Accuracy and Repeatability of Refractive Error Estimates Depend on the Measurement Principle of Autorefractors? Transl Vis Sci Technol. 2021 Jan 5;10(1):2. doi: 10.1167/tvst.10.1.2. PMID: 33505769; PMCID: PMC7794271.
10. Gurnani B, Kaur K. Autorefractors. 2023 Jun 11. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2026 Jan–. PMID: 35593828.
11. Thibos LN. Principles of Hartmann-Shack aberrometry. J Refract Surg. 2000 Sep-Oct;16(5):S563-5. doi: 10.3928/1081-597X-20000901-14. PMID: 11019873.
12. Molebny VV, Panagopoulou SI, Molebny SV, Wakil YS, Pallikaris IG. Principles of ray tracing aberrometry. J Refract Surg. 2000 Sep-Oct;16(5):S572-5. doi: 10.3928/1081-597X-20000901-17. PMID: 11019876.
13. Saad A, Frings A. Refractive assessment by wavefront aberrometry compared to subjective refraction in PRK patients. Graefes Arch Clin Exp Ophthalmol. 2025 Sep;263(9):2679-2687. doi: 10.1007/s00417-025-06868-9. Epub 2025 Jun 25. PMID: 40560290; PMCID: PMC12513918.
14. Reinstein DZ, Neal DR, Vogelsang H, Schroeder E, Nagy ZZ, Bergt M, Copland J, Topa D. Optimized and wavefront guided corneal refractive surgery using the Carl Zeiss Meditec platform: the WASCA aberrometer, CRS-Master, and MEL80 excimer laser. Ophthalmol Clin North Am. 2004 Jun;17(2):191-210, vii. doi: 10.1016/j.ohc.2004.03.005. PMID: 15207562.
15. Piñero DP, Sánchez-Pérez PJ, Alió JL. Repeatability of measurements obtained with a ray tracing aberrometer. Optom Vis Sci. 2011 Sep;88(9):1099-105. doi: 10.1097/OPX.0b013e3182223788. PMID: 21666525.
16. Rotsos T, Grigoriou D, Kokkolaki A, Manios N. A comparison of manifest refractions, cycloplegic refractions and retinoscopy on the RMA-3000 autorefractometer in children aged 3 to 15 years. Clin Ophthalmol. 2009;3:429-31. doi: 10.2147/opth.s5145. Epub 2009 Aug 3. PMID: 19684866; PMCID: PMC2724033.
17. Al-Tuwairqi WS, Ogbuehi KC, Razzouk H, Alanazi MA, Osuagwu UL. Agreement Between Autorefraction and Subjective Refraction in Keraring-Implanted Keratoconic Eyes. Eye Contact Lens. 2017 Mar;43(2):116-122. doi: 10.1097/ICL.0000000000000244. PMID: 26825280.
18. Davidova P, Rostom M, Timoceanu LG, Schug T, Kaiser KP, Jandewerth T, Kohnen T. Subjective and Objective Refraction Using Autorefraction and Two Wavefront-based Aberrometers in Extended-Depth-of-Focus and Simultaneous Vision Intraocular Lenses. Am J Ophthalmol. 2026 May;285:335-342. doi: 10.1016/j.ajo.2026.02.023. Epub 2026 Feb 18. PMID: 41720231.
19. Visser N, Berendschot TT, Verbakel F, Tan AN, de Brabander J, Nuijts RM. Evaluation of the comparability and repeatability of four wavefront aberrometers. Invest Ophthalmol Vis Sci. 2011 Mar 10;52(3):1302-11. doi: 10.1167/iovs.10-5841. PMID: 21051697.
20. Zhang X, Zhou Y, Yang J, Wang Y, Yang W, Gao L, Xiang Y, Zhang F. The distribution of refraction by age and gender in a non-myopic Chinese children population aged 6-12?years. BMC Ophthalmol. 2020 Nov 7;20(1):439. doi: 10.1186/s12886-020-01709-1. PMID: 33160315; PMCID: PMC7648976.
21. Aluyi-Osa G, Musa MJ, Zeppieri M. Jackson Cross Cylinder. 2023 May 22. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2026 Jan–. PMID: 36508527.
22. Hastings GD, Marsack JD, Nguyen LC, Cheng H, Applegate RA. Is an objective refraction optimised using the visual Strehl ratio better than a subjective refraction? Ophthalmic Physiol Opt. 2017 May;37(3):317-325. doi: 10.1111/opo.12363. Epub 2017 Mar 30. PMID: 28370389; PMCID: PMC5469359.
23. Hervella L, Villegas EA, Prieto PM, Artal P. Assessment of subjective refraction with a clinical adaptive optics visual simulator. J Cataract Refract Surg. 2019 Jan;45(1):87-93. doi: 10.1016/j.jcrs.2018.08.022. Epub 2018 Oct 8. PMID: 30309774; PMCID: PMC6320260.
24. Bennett JR, Stalboerger GM, Hodge DO, Schornack MM. Comparison of refractive assessment by wavefront aberrometry, autorefraction, and subjective refraction. J Optom. 2015 Apr-Jun;8(2):109-15. doi: 10.1016/j.optom.2014.11.001. Epub 2014 Dec 11. PMID: 25498534; PMCID: PMC4401825.
25. Cooper J, Citek K, Feldman JM. Comparison of refractive error measurements in adults with Z-View aberrometer, Humphrey autorefractor, and subjective refraction. Optometry. 2011 Apr;82(4):231-40. doi: 10.1016/j.optm.2010.09.013. PMID: 21439490.
26. Bamdad S, Momeni-Moghaddam H, Abdolahian M, Piñero DP. Agreement of wavefront-based refraction, dry and cycloplegic autorefraction with subjective refraction. J Optom. 2022 Jan-Mar;15(1):100-106. doi: 10.1016/j.optom.2020.08.008. Epub 2020 Sep 28. PMID: 32896507; PMCID: PMC8712579.
27. Lin HZ, Chen CC, Lee YC. Comparisons of wavefront refraction, autorefraction, and subjective manifest refraction. Tzu Chi Medical Journal. 2013 Mar 1;25(1):43-6. doi: 10.1016/j.tcmj.2013.01.006.
28. Doyle M, O'Dwyer V, Moore M, Harrington S. Accuracy and repeatability of autorefraction in young adults: a comparison of cycloplegic and non-cycloplegic methods. Clin Exp Optom. 2026 Apr;109(3):462-472. doi: 10.1080/08164622.2025.2542321. Epub 2025 Aug 10. PMID: 40785048.
29. Roque A, Nunes AF, Nascimento H, Martinez-Perez C. Instrument-based, non-cycloplegic versus cycloplegic refraction in pediatric and young adult populations (?25 years): A systematic review and meta-analysis. Adv Ophthalmol Pract Res. 2025 Nov 14;6(1):56-67. doi: 10.1016/j.aopr.2025.11.004. PMID: 41647053; PMCID: PMC12870854.
30. Jones D, Chow A, Fadel D, Gonzalez Meijome JM, Grzybowski A, Kollbaum P, Loughman J, Wolffsohn J. IMI-Instrumentation for Myopia Management. Invest Ophthalmol Vis Sci. 2025 Jul 1;66(9):7. doi: 10.1167/iovs.66.9.7. PMID: 40600762; PMCID: PMC12227030.
31. Umaefulam V, Safi S, Lingham G, Gordon I, Mueller A, Krishnam NS, Alves Carneiro VL, Yu M, Evans JR, Keel S. Approaches for delivery of refractive and optical care services in community and primary care settings. Cochrane Database Syst Rev. 2024 May 29;5(5):CD016043. doi: 10.1002/14651858.CD016043. PMID: 38808577; PMCID: PMC11134311.
32. Shane TS, Knight O, Shi W, Schiffman JC, Alfonso EC, Lee RK. Treating uncorrected refractive error in adults in the developing world with autorefractors and ready-made spectacles. Clin Exp Ophthalmol. 2011 Nov;39(8):729-33. doi: 10.1111/j.1442-9071.2011.02546.x. Epub 2011 Apr 21. PMID: 22050561; PMCID: PMC4139100.
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