Disability glare in soft multifocal contact lenses

Purpose

The study investigated the effect of the design of multifocal contact lenses on the sensitivity to contrast and disability glare.

Methods

Contrast sensitivity was measured in 16 young adults (mean age: 25.5 ± 2.5 years) at a distance of 2 m under two conditions: no-glare and glare. Two designs (Center Near and Center Distance) of the Biofinity soft contact lens were used to simulate correction for presbyopes, while a correction with single vision trial lenses and contact lenses acted as controls.

Results

The design of the used multifocal contact lenses had a significant influence on the log area under the curve of the contrast sensitivity function (AUC-CSF). Compared to the spectacle lens correction, the AUC-CSF was significantly reduced, in case CS was measured with the Center Near design lens, under the no-glare (p < 0.001) and the glare condition (p: p < 0.001). In case of the Center Distance design contact lens, the AUC-CSF was significantly smaller in case CS was tested under glare (p = 0.001). Disability glare (DG) was depending on the spatial frequency and the design of the multifocal lens, while the Center Distance design produced higher amounts of DG (p < 0.001), compared to the other used corrections.

Conclusion

The optical design of a multifocal contact lenses has a significant impact on the contrast sensitivity as well as the disability glare. In order to dispense the best correction in terms of contact lenses, the sensitivity to contrast under no-glare and glare conditions should be tested a medium spatial frequencies.