Can Tinted Lenses Be Used to Manipulate Pupil Size and Visual Performance When Wearing Multifocal Contact Lenses?

• Published in: Clinical optometry (Auckland) 2020-01, Vol.12, p.27-35
• Main Authors: Park, Hyung Min, Ryu, Young Uk, Park, Inn-Jee, Chu, Byoung Sun
• Format: Article
• Language: English
• Subjects: accommodative responses; Contact lenses; Diabetic retinopathy; Light; multifocal contact lens; Original Research; Presbyopia; pupil size; Quality of life; tinted lens; vision
• ISSN: 1179-2752; 1179-2752
• DOI: 10.2147/OPTO.S245715

The purpose of this study is to investigate the effect of wearing neutral density (ND) filters with different transmittance levels over multifocal contact lenses (MTF CLs) on pupil size, visual functions and the dynamic accommodative response under daylight conditions in early presbyopes. Seventeen individuals aged between 40 and 48 years (mean age 42.35±2.62 years) were recruited to participate in this study. This study involved a repeated-measures design with two within-subject factors: optical condition (which had five levels), and fixation distance (which had three levels). The five optical conditions were no correction (baseline), MTF CL wear, MTF CL wear + 0.3 ND filter (transmission [Tv]=48.38%), MTF CL wear + 0.6 ND filter (Tv=27.12%) and MTF CL wear + 0.9 ND filter (Tv=14.58%). The three fixation distances were 3 m, 40 cm and 20 cm. Outcome measures were pupil size, the measured accommodative response (optical aid + physiological accommodation), distance visual acuity (VA), near VA and contrast sensitivity (CS). There was no effect of optical condition on the accommodative response; however, there was a significant effect of fixation distance. (Accommodative response was 0.44±0.29, 1.83±0.37 and 4.03±0.46 D for fixation distances of 3 m, 40 cm and 20 cm, respectively; p