Differences in the optical properties of photochromic lenses between cold and warm temperatures

Effect of Photochromic Contact Lens Wear on Indoor Visual Performance and Patient Satisfaction

INTRODUCTION

To quantitatively assess visual performance and patient satisfaction during photochromic contact lens (CL) wear in an indoor environment.

METHODS

This observational study comprised 82 eyes of 41 healthy subjects (mean age ± standard deviation, 21.7 ± 0.7 years) who had no ophthalmic diseases except for refractive errors at Kitasato University in 2021. We prospectively compared visual acuity, kinetic visual acuity, functional (time-dependent) visual acuity, the maintaining rate of visual acuity, the response time, contrast sensitivity function, higher-order aberrations, and patient satisfaction score for overall vision in such subjects during photochromic and non-photochromic CL wear in such an environment.

RESULTS

The kinetic visual acuity at 30 km/h was 0.32 ± 0.21 and 0.41 ± 0.24 in the photochromic and non-photochromic CL groups, respectively (p = 0.008). The kinetic visual acuity at 60 km/h was 0.32 ± 0.21 and 0.41 ± 0.24, respectively (p = 0.034). The functional visual acuity was 0.00 ± 0.21 and 0.05 ± 0.25, respectively (p = 0.030). The average response time was 1.19 ± 0.15 s and 1.23 ± 0.15 s, respectively (p = 0.029). The patient satisfaction score for overall visual performance was 4.22 ± 0.11 and 3.59 ± 0.68, respectively (p < 0.001). Otherwise, we found no significant differences in visual acuity, the maintaining rate, higher-order aberrations, or contrast sensitivity function (p = 0.116, p = 0.053, p = 0.371, or p = 0.943). We found no apparent complications such as ocular discomfort, superficial punctate keratitis, conjunctival injection, or infectious keratitis during the observation period.

CONCLUSIONS

According to our experience, the photochromic CL showed good visual quality, especially in terms of kinetic and functional visual acuities and subsequent high patient satisfaction, even in an indoor environment, suggesting its viability of visual correction not only in daily activities but also in indoor sports activities.