Visual comparison of an artificial pupil contact lens to monovision.

PURPOSE: To assess and compare the effects of contact-lens based artificial pupil design and monovision correction on visual performance.

METHODS

In a cross-over study design, 22 presbyopic patients (age range 50 to 64 years) were evaluated using artificial pupil contact lens on the non-dominant eye and monovision. After 1 month, binocular distance visual acuity (BDVA), binocular near visual acuity (BNVA), defocus curve, binocular distance contrast sensitivity, binocular near contrast sensitivity, and stereoacuity were measured, under photopic conditions (85 cd/m2), in each patient after contact lens fitting. Moreover, BDVA and binocular distance contrast sensitivity were examined under mesopic conditions (5 cd/m2).

RESULTS

Average artificial pupil contact lens and monovision BDVA were 0.02 ± 0.04 and 0.00 ± 0.09 logMAR for photopic conditions, and 0.16 ± 0.06 and 0.13 ± 0.12 logMAR for binocular near visual acuity under mesopic conditions, respectively. No statistically significant differences were found between the two types of lenses at distance for both lighting levels (p > 0.05), but there were, however, significant differences at intermediate distances and near vision (p < 0.05). Binocular distance contrast sensitivity revealed statistically significant differences between artificial pupil contact lens and monovision for 1.5 cycles per degree (cpd) under photopic conditions, and 12 and 18 cpd under mesopic conditions (p < 0.05), respectively. Statistically significant differences for all spatial frequencies except for 1.5 cpd were found at near vision (p < 0.05). The mean values of stereoacuity obtained for artificial pupil contact lens (221 ± 32 sec arc) were slightly worse than for monovision correction (210 ± 49 sec arc), and statistically significant differences were not found (p = 0.23).

CONCLUSIONS

Monovision performed better than an artificial pupil contact lens of the same material for near visual acuity and near contrast sensitivity. Only, the artificial pupil contact lens provides better intermediate visual acuity.