Chinese Visual Acuity Chart

Purpose. To select ten Chinese optotypes with similar legibility to be used in the construction of a Chinese Visual Acuity Chart and to compare the visual acuity (VA) outcomes measured using this Chinese Visual Acuity Chart with those assessed using existing vision charts. Methods. The relative legibility of 27 Chinese optotypes were assessed on 30 subjects aged 12 to 75. Based on the results of this legibility study, ten optotypes were selected. A Chinese Visual Acuity Chart in logMAR progression was designed and constructed using these ten optotypes. Interaction bars were incorporated into this vision chart, which is for use at a working distance of four metres. In a comparability study, the visual acuity of 33 subjects were measured using the Chinese Visual Acuity Chart, the University of Waterloo Chart and the Bailey-Lovie logMAR Chart. Finally, in a repeatability study, four VA measurements on each of the three vision charts were performed on ten subjects. Results. Ten Chinese optotypes with relative legibility of 70% to 95% were selected for the construction of a Chinese Visual Acuity Chart. Visual acuity assessments using the Chinese Visual Acuity Chart were found to be comparable to those measured using the University of Waterloo Visual Acuity Chart and the Bailey-Lovie Chart. The repeatability of VA assessment using the Chinese Visual Acuity Chart was also similar to those of the two other vision charts. Conclusions. The performance of the new Chinese Visual Acuity Chart is statistically and clinically comparable to internationally recognized acuity charts and can be used to assess subjects who read Chinese characters but not the Roman alphabet.