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

PURPOSE: To quantify the quality of vision achieved with multifocal and bifocal contact lenses.

METHODS

We analyzed differential light sensitivity by computerized automatic perimetry in 21 patients wearing monofocal soft contact lenses (group 1, controls) and multifocal and bifocal contact lenses (groups 2 and 3, respectively). Seven patients each were fitted with multifocal or bifocal contact lenses; seven patients were without contact lenses (without correction for testing the visual periphery and with near-vision correction using monofocal contact lens for testing the central 30 degrees of vision). The type of correction was randomly changed in a crossover fashion so that each eye was examined at different times with different corrections. Humphrey 640 VFA computerized automated perimetry was used to test visual fields at baseline, 45 days, and 3, 4.5, and 6 months.

RESULTS

A statistically significant difference was found between the global sensitivities (GS) of the central visual field in patients with near-vision monofocal contact 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 there is reduced differential light sensitivity in the central 30 deg of the visual field with bifocal contact lenses compared with multifocal contact lenses and monofocal contact lenses (controls).