Objective: The present study was designed to examine the visual acuity (VA) and contrast sensitivity function (CSF) under three refractive correction methods, the visual performance and vision quality under different correction methods were compared and analyzed.
Methods: Twenty three college students with myopia (41 eyes, myopia range: -1.25 D approximately 9.25 D; astigmatism < 0.50 D) were enrolled and fully corrected by three different methods: 1) spectacles with resin lens material (SP); 2) soft contact lens (SCL); 3) rigid gas-permeable lens (RGP). The distant and near LogMar VA and CSF were examined. To avoid the subjective bias, the correction procedure was randomly selected and the VA chart and CSF chart used had the same pattern but different letters' organization or directions.
Results: The best corrected distant VA was significantly higher in RGP wearing eyes than those in the Soft-CL and SP wearing eyes (P < 0.01 and P < 0.05, respectively). No statistically significant difference was detected between the SP and SCL wearing eyes. There was no significant difference in the near VA among these three conditions, although the near VA in RGP group was slightly better than that in the SCL condition. There was no significant difference in CSF value at low spatial frequencies (1.5 cpd and 3 cpd) among these three conditions. However, at middle and high spatial frequencies (6 cpd, 12 cpd and 18 cpd), the RGP curve was the highest and followed by the SCL and SP curves.
Conclusion: RGP correction offers the best visual acuity quality for myopia subjects. The CSF assessment can be used as an indirect method to evaluate the quality of corrected retinal image.