Quality of vision with presbyopic contact lens correction: subjective and light sensitivity rating

Purpose: To quantify the quality of vision achieved with multifocal and bif ocal contact lenses. Methods: We analyzed differential light sensitivity by computerized automatic perimetry in 21 patients wearing monofocal soft con tact lenses (group 1, controls) and multifocal and bifocal contact lenses ( groups 2 and 3, respectively). Seven patients each were fitted with multifo cal or bifocal contact lenses; seven patients were without contact lenses ( without correction for testing the visual periphery and with near-vision co rrection using monofocal contact lens for testing the central 30 degrees of vision). The type of correction was randomly changed in a crossover fashio n so that each eye was examined at different times with different correctio ns. Humphrey 640 VFA computerized automated perimetry was used to test visu al fields at baseline, 45 days, and 3, 4.5, and 6 months. Results: A statis tically significant difference was found between the global sensitivities ( GS) of the central visual field in patients with near-vision monofocal cont act lenses and with bifocal contact lenses (P=0.0273) and between the GS of the central visual fields with multifocal contact lenses and with bifocal contact lenses (P=0.0261). In both cases, the GS were significantly reduced with bifocal contact lenses (total GS: group 1, 11256 dB (Decibels); group 2, 11154 dB; group 3, 10679 dB). Conclusions: The results indicate that th ere is reduced differential light sensitivity in the central 30 deg of the visual field with bifocal contact lenses compared with multifocal contact l enses and monofocal contact lenses (controls).