To compare visual acuity and intraocular straylight after implantation of clear and photochromic intraocular lenses (IOLs) in a mesopic lighting condition.

Clear IOLs were implanted in 95 eyes of 72 patients (clear IOL group), and photochromic IOLs were implanted in 22 eyes of 16 patients (photochromic IOL group). Best-corrected visual acuity (BCVA) was measured indoors before surgery and 1 month after surgery. Straylight values were measured indoors before surgery and 1 and 2 months after surgery using the C-quant straylight meter (Oculus GmbH, Wetzlar, Germany).

There were no significant differences between the 2 groups in BCVA at 1 month postoperatively ( p = 0.587). Mean straylight values of clear and photochromic IOL groups were 2.76 ± 1.89 log (s) and 2.88 ± 2.04 log (s) preoperatively, 1.39 ± 0.84 log (s) and 1.32 ± 0.26 log (s) at 1 month postoperatively, and 1.43 ± 0.92 log (s) and 1.45 ± 0.50 log (s) at 2 months postoperatively. There were no significant differences between the 2 groups in indoor straylight values ( p = 0.778, 0.709, 0.929, before surgery, 1 and 2 months after surgery respectively). Repeated-measure analysis of straylight values also showed no significant difference between the 2 groups ( p > 0.05).

There were no significant differences in BCVA and straylight values between clear and photochromic IOL groups under a mesopic light condition. Therefore, photochromic IOL could be suitable choice for cataract patients who spend significant time under mesopic conditions.