Pinhole contacts

The Kamra intracorneal inlay (AcuFocus) increases depth-of-focus through smalldiameter aperture optics to correct presbyopia. Questions remain about the optimal design of such systems. Accordingly, researchers evaluate the effects of four different contact lens-based artificial pupil designs on visual performance in 33 presbyopic patients. The mean uncorrected and corrected distance visual acuity ranged from 0.04 ± 0.05 (SD) to −0.01 ± 0.04 logMAR and from −0.02 ± 0.05 to −0.05 ± 0.03 logMAR, respectively. The uncorrected near visual acuity and distancecorrected near visual acuity ranged from 0.37 ± 0.11 to 0.42 ± 0.20 logMAR and from 0.35 ± 0.17 to 0.38 ± 0.12 logMAR, respectively. The difference in binocular distance contrast sensitivity was statistically significant between the pinhole systems and the control group (distance-corrected patients without pinhole lens) for six cycles per degree (cpd), 12 cpd, and 18 cpd. For near vision, differences were also significant for 3 cpd at the two luminance levels (P.05). The researchers conclude that soft contact lens apertures provide good visual acuity at distance, functional intermediate vision, and poor near visual acuity and stereoacuity. An improvement in visual performance with decreasing pupil diameter was not found.

 S García-Lázaro et al., JCRS, 'Visual function through 4 contact lens-based pinhole systems for presbyopia', Vol 38, No. 5, 858-865.