Optimal Optotype Structure for Monitoring Visual Acuity

Open access


To date, there are no generally accepted optotypes for monitoring visual acuity. All common optotypes are not completely suitable for some reasons. The tasks requiring visual monitoring - investigation of visual development, early diagnostics, assessment of treatment - impose heavy demands on the test stimuli. They must be: (1) suitable for patients of any age; (2) convenient for repeatable examinations; and (3) accurate enough for revealing the smallest physiologically significant changes of visual acuity. From theoretical consideration, one could conclude that the optotypes for monitoring visual acuity should be designed for measuring visual resolution but not recognition, unlike most popular optotypes. The best optotypes for visual resolution are gratinglike stimuli whose recognition could only be based on the high frequency part of the Fourier spectrum around the characteristic frequency (not on the low-frequency components). On the basis of theoretical analysis we elaborated modified 3-bar optotypes, which minimise the possibility of using low-frequency cues for stimulus recognition. In this paper we present the results of theoretical and experimental comparison of these optotypes with the two widely used ones: tumbling-E and standard 3-bar targets. According to the data obtained, our modified optotypes seem to be better than other investigated ones for monitoring visual acuity.

If the inline PDF is not rendering correctly, you can download the PDF file here.

  • Anderson R. S. Thibos L. N. (1999a). The relationship between acuity for gratings and for tumbling-E letters in peripheral vision. J. Opt. Soc. Amer. A 16 2321-2333.

  • Anderson R. S. Thibos L. N. (1999b). Sampling limits and critical bandwidth for letter discrimination in peripheral vision. J. Opt. Soc. Amer. A 16 2334-2342.

  • Bailey I. L. Lovie J. E. (1976). New design principles for visual acuity letter charts. Amer. J. Optom. Physiol. Opt. 53 740-745.

  • Bennett A. G. (1964). Ophthalmic test types. A review of previous work and discussions on some controversial questions. Brit. J. Physiol. Opt. 22 (4) 238-271.

  • Bondarko V. M. Danilova M. V. (1997). What spatial frequency do we use to detect the orientation of a Landolt C? Vis. Res. 37 2153-2156.

  • Campbell F. W. Green D. G. (1965). Optical and retinal factors affecting visual resolution. J. Physiol. 181 (3) 576-593.

  • Colenbrander A. (2008) The historical evolution of visual acuity measurement. Vis. Impair. Res. 10 (2-3) 57-66.

  • Green J. (1868). On a new series of test-letters for determining the acuteness of vision. Trans. Amer. Ophthalmol. Soc. 1 (4-5) 68-71.

  • Heinrich S. P. Bach M. (2013). Resolution acuity versus recognition acuity with Landolt-style optotypes. Graefes Arch. Clin. Exp. Ophthalmol. 251 (9) 2235-2241.

  • Hyvarinen L. Nasanen R. Laurinen P. (1980). New visual acuity tests for pre-school children. Acta Ophthalmol. 58 (4) 507-511.

  • ISO (1994). ISO 8596. International Standard. Ophthalmic optics. Visual acuity testing. Standard optotype and its presentation. Geneve. (2nd edition: Geneve 2009).

  • ISO (1994). ISO 8597. International Standard. Optics and optical instruments. Visual acuity testing. Method of correlating optotypes. Geneve.

  • Koskin S. A. (2009). The system of visual acuity measurements for medi¬cal expertise [Коскин С. А. Система определения остроты зрения в целях врачебной экспертизы]. MD Thesis[ S.M. Kirov Military Medical Academy St. Petersburg. 48 pp. (in Russian).

  • Landolt E. (1889). Tableau d’optotypes pour la determination de l’acuite visuelle. Societe Francais.

  • Lebedev D. S. (2015). A model of orientation recognition mechanisms for the 3-bar two-grade optotypes [Модель механизма распознавания ориентации 3-полосных двухградационных оптотипов]. Sensornye sistemy [Сенсорные системы] 29 (4) 309-320 (in Russian).

  • Lebedev D. S. Belozerov A. E. Rozhkova G. I. (2010). The optotypes for an accurate assessment of visual acuity [Оптотипы для точной оценки остроты зрения]. Patent № 2447826; 07.12.10 (in Russian).

  • Pirenne M. H. (1962). Visual acuity. The Eye 2 175-195.

  • Plainis S. Tzatzala P. Orphanos Y. Tsilimbaris M. K. (2007) A modified ETDRS visual acuity chart for European-wide use. Optom. Vis. Sci. 84 (7) 647-653.

  • Polat U. Sagi D. (1993). Lateral interactions between spatial channels: Suppression and facilitation revealed by lateral masking experiments. Vis. Res. 33 (7) 993-999.

  • Rozhkova G. I. (2013). Visual acuity measurement: Account of the optotype structure. 36th European Conference on Visual Perception 2013. Bremen Germany. 25-29 August. Perception 42 Suppl. 69.

  • Rozhkova G. I. Lebedev D. S. (2010). Is it rational to use Landolt C and Snellen E as the optotypes in the modern-day visual acuity measurements for early diagnostics? In: Proceedings of the 1st World Congress on Controversies in Ophthalmology Prague Czech Republic March 4-7 p. 16.

  • Rozhkova G. I. Belozerov A. E. Lebedev D. S. (2012).Visual acuity measurement: uncertain effect of the low-frequency components of the optotype Fourier-spectra [Рожкова Г. И. Белозеров А. Е. Лебедев Д. С. Измерение остроты зрения: неоднозначность влияния низко¬частотных составляющих спектра Фурье оптотипов]. Sensomye sistemy [Сенсорные системы] 26 (2) 160-171 (in Russian).

  • Rozhkova G. Lebedev D Gracheva M. Rychkova S. (2014). Advantages of employing specially modified 3-bar stimuli for visual acuity monitoring in adults and children: Test-retest reliability. 37th European Conference on Visual Perception Belgrad Serbia 24-28 August. Perception 43 Suppl. 34.

  • Shelepin Ju. E. Kolesnikova L. N. Levkovich Ju. I. (1985). Visio- contrastometry [Шелепин Ю. E. Колесникова Л. H. Левкович Ю. И. Визоконтрастометрия.] Nauka Leningrad. 103 pp. (in Russian).

  • Shelepin Ju. E. Glezer V. D. Bondarko V. M. Pavlovskaja M. B. Vol I. A. Danilov Ju. P. (1992) Spatial Vision [Шелепин Ю. E. Глезер В. Д. Бондарко В. М. Павловская М. Б. Вол И. А. Данилов Ю. П. Пространственное зрение] In: Byzov A. L. (Ed.). Vision Physiology [Физиология зрения. Под ред. А. Л. Бызова]. Nauka Moscow pp. 528-585. (in Russian)

  • Shelepin Ju. E. Volkov V. V. Makulov V. B. Kolesnikova L. N. Pauk V. N. (1987). Measuring of functional possibilities of human visual system [Øåëåïèí Þ. Å. Âîëêîâ Â. Â. Ìàêóëîâ Â. Á. Êîëåñíèêîâà Ë. Í. Ïàóê Â. Í. Èçìåðåíèå ôóíêöèîíàëüíûõ âîçìîæíîñòåé çðèòåëüíîé ñèñòåìû ÷åëîâåêà]. Academy of Sciences Herald USSR [Âåñòíèê ÀÍ ÑÑÑÐ] 9 63-72 (in Russian).

  • Sloan L. L. (1959). New test charts for the measurement of visual acuity at far and near distances. Amer. J. Ophthalmol. 48 (6) 807-813.

  • Snellen H. (1862). Test-types for the Determination of the Acuteness of Vision. P. W. van de Weijer Utrecht. 44 pp.

  • Stiers P. Vanderkelen R. Vandenbussche E. (2003). Optotype and grating visual acuity in preschool children. Invest. Ophthalmol. Vis. Sci. 44 4123-4130.

  • Stiers P. Vanderkelen R. Vandenbussche E. (2004). Optotype and grating visual acuity in patients with ocular and cerebral visual impairment. Invest. Ophthalmol. Vis. Sci. 45 4333-4339.

  • USAF (1951). USAF-1951. United States Air Force 3-bar resolution test chart.

  • Wittich W. Overbury O. Kapusta M. A. Watanabe D. H. (2006). Differences between recognition and resolution acuity in patients undergoing macular hole surgery. Invest. Ophthalmol. Vis. Sci. 47 3690-3694.

Journal information
Impact Factor

CiteScore 2018: 0.3

SCImago Journal Rank (SJR) 2018: 0.137
Source Normalized Impact per Paper (SNIP) 2018: 0.192

Cited By
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 269 175 15
PDF Downloads 129 90 4